CA1313397C - Disposable bioelectrochemical electrodes - Google Patents
Disposable bioelectrochemical electrodesInfo
- Publication number
- CA1313397C CA1313397C CA000606230A CA606230A CA1313397C CA 1313397 C CA1313397 C CA 1313397C CA 000606230 A CA000606230 A CA 000606230A CA 606230 A CA606230 A CA 606230A CA 1313397 C CA1313397 C CA 1313397C
- Authority
- CA
- Canada
- Prior art keywords
- disposable element
- electrodes
- filter
- analytical equipment
- substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/001—Enzyme electrodes
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/02—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving viable microorganisms
- C12Q1/04—Determining presence or kind of microorganism; Use of selective media for testing antibiotics or bacteriocides; Compositions containing a chemical indicator therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
- G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
- G01N33/54366—Apparatus specially adapted for solid-phase testing
- G01N33/54373—Apparatus specially adapted for solid-phase testing involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
- G01N33/5438—Electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S436/00—Chemistry: analytical and immunological testing
- Y10S436/806—Electrical property or magnetic property
Abstract
ABSTRACT
A disposable element is provided for use in analytical equipment for electrochemical determination of biological cells. The disposable element comprises a working electrode, a reference electrode, and a filter for retention of solids in the vicinity of the electrodes. The analytical equipment with disposable elements can be used for respiratory assays, enzyme assays or immunoassays, among other uses.
In a variation, the disposable element comprises a reference electrode, working electrode and fusible link.
A disposable element is provided for use in analytical equipment for electrochemical determination of biological cells. The disposable element comprises a working electrode, a reference electrode, and a filter for retention of solids in the vicinity of the electrodes. The analytical equipment with disposable elements can be used for respiratory assays, enzyme assays or immunoassays, among other uses.
In a variation, the disposable element comprises a reference electrode, working electrode and fusible link.
Description
1313~97 The present invention xelates to analytical equipment for performing electrochemical assays on microbial samples. In particular, the present invention relates to electrodes for use in such analytical equipment.
Accurate and rapid determination of microbial activity is essential in many areas, including pollution control; ~uality assurance in the food, drink and drugs industries; and clinical analysis of bodily fluids and other medical samples.
For a long time, the standard method for the enumeration of bacteria has been an agar plate count. This method has many disadvantages, especially the time needed to obtain results~
Even with the fastest growth, 18 hours is needed for visible colony formation, and then there is the task of counting the colonies.
There have been proposals to employ bioelectrochemical cells or fuel cells for assaying of microbiological samples. For example, amperometric determination of viable cell numbers based on sensing microbial respiration is described in Appl Microbiol Biotechnol (1981) 12, 97; the use of a microbial fuel cell for the rapid enumeration of bacteria is described in Appl Microbiol Biotechnol (1988) 28, ~6; and an investigation of a simple amperometric electrode system to rapidly quantify and detect bacteria is described in J Appl ~313397 Bacteriol (1989) 66, 49. Further aspects of amperometric bioassay systems are described in EP 190470 and 238322, and GB 2181451 and 2181558, among other examples. Some of these systems employ a filter to capture microbial cells at the electrodes, after which the determination is effected.
The present invention provides analytical equipment for a bioelectrochemical determination of microorganisms or other cells in a liquid sample using a working electrode and a reference electrode. The working electrode, the reference electrode, and a filter for retention of solids in the vicinity of the electrodes are provided as a disposable element. The analytical equipment has receiving mea~s for releasably receiving the disposable element.
Since the electrodes and filter are provided as a disposable element, the user of the analytical equipment does not have to set up the electrodes and arrange the filter. A greater degree of certainty and reliablity is introduced by employing the disposable element, which may be carefully manufactured as a sealed unit under controlled conditions to a consistent quality.
The disposable elements themselves are part of this invention, and in further aspects, the present invention provides methods of assay for microorganisms or other cells which methods employ the disposable elements.
The disposable element in conjunction with the associated analytical equipment is suitably designed for page 3 ~313397 through-flow use to ~eap any cells in the sample, e~fecting concentration and allowing washing. At p~esent a generally planar disposable element is preferred, especially for use with the electrodes and filter extending generally horizontally, and with flow through the element being generally vertical.
The filter of the disposable element may be interposed between opposed electrodes, or in alternative constructions, the filter can be upstream of the electrodes. The choice of filter material depends on three main criteria: good retention of biological cells (90% or better); adequate flow rate at a given pressure:
and reasonable resistance to blockage. The last two criteria affect the volume of a particular sample that can be introduced and hence the degree of concentration obtainable .
Particularly suitable filters are depth filters, especially glass ~ibre filters (for example, as manufactured by Whatman or Millipore). Other filters can be employed, such as membrane filters, charge-modified filters, and so on. Alternative forms of filters might be adopted, including capture matrices such as antibodies or lectins immobilised on beads.
The filter may be housed in a housing made from two halves fitted together. These two halves can be made in an injection moulding process. Furthermore, meshes can be employed to encourage the desired flow and distribution of liquid through the filter.
The wo~king electrode may be based on known materials.
It is possible to use noble metals such as gold or platinum, but it is generally preferred to use less expensive materials for the manufacture of disposable devices. A suitable material may be gLaphite felt lfor example, RVG2000 Le Carbone). However, graphite felt tends to provide high electrical resistance, and in a page 4 1313397 prefereed aspect of this invention, it has been found that good results are available from the use of printed carbon electrodes. In a particularly preferred aspect, one or more of the electrodes is screen printed.
The reference electrode typically comprises silver and silvec chloride (Ag/AgCl), or mercury and mercury chloride (saturated calomel electrode, SCE). Such systems have known, absolute electrode potentials in aqueous media. It is preferred to use the reference electrode alone to complete the external circuit, particularly when currents are small -6 or less). Especially preferred is a printed silver/silver chloride reference electrode.
Since the potential of the reference electrode can drift as current passes, it is possible to provide a counter electrode through which the bulk of the current can be directed. Suitable materials for counter electrodes include platinum, gold or silver. Where a counter electrode is used, it is sufficient that the reference electrode has enough surface area to establish the reference potential.
Screen-printed electrodes present a number of advantages: there is more scope for optimising electrode behaviour and configuration, and a close proximity of working and reference electrodes can be achieved. The resistances are lower than with graphite felt, and it is considerably easier to make contacts to the electrodes. The response of printed electrodes to bacteria are of the same order as those obtained with graphite felt, but a little lower. However, this result i6 compensated for by better and more controllable background currents.
The reference and/or working electrode and/or counter electrode is suitably formed by printing or otherwise 13~3~97 page S
coating onto an ineet subs~rate, such as a fibre (for instance glass fibre) matrix or plastics (for instance polyvinyl chloride, "pvc") substrate. Permeability of the electrode can be an advantage, but it may be solid, provided that fluid can pass across its surface. When the electrode serves no filtering function it is equally possible to use a solid electrode with one or more apertures for passage of liquid, or to use a network or mateix allowing free passage of liquid through all parts of the electrode.
In one embodiment, the working electrode is carbon felt, laid over a filter, with a matrix reference electrode positioned opposite the working electrode. The whole is placed in a housing and the sample is fed in through an entry port. Thi~ diffuses across the filter allowing the surface areas of both electrodes to be effectively used. In practice, a buffer will generally be passed through in both direction to purge any air present, be~ore the sample is introduced, again, in eithee direction. This is then usefully followed by washing with buffer and introduction of compounds acting as mediators. as required.
In an alternative embodiment, the electrode through which the sample is introduced has a single aperture preferably in the centre, while an opposite electrode allows escape of fluid about its periphery, preferably through more than one aperture, for example eight apertures.
In another embodiment, a working electrode of carbon printed ink i8 interdigitated with a reference electrode printed in si.lver/silvee chloride ink. For example a star-shape electrode interdigitates with the other electrode. The close proximity of reference and working electrodes allows qood control of the potential at the working electrode surface. A counter electrode 13~3~97 page 6 can be provided by a disc printed in silver ink. The electrodes are suitably printed onto 0.5mm thick pvc, and cut into discs. Apertures punched in the discs allow liquid flow: a central aperture in the working/reference electrode disc and eight peripheral apertures in the other disc being suitable. The discs can then be assembled in a filter electrode holder on either side of a glass-fibre filter disc, to give a disposable element.
In a yet further embodiment, the disposable element comprises a pvc or other plastics substrate with two concentric electrodes comprising a working electrode, preferably scceen-printed in organic-based carbon ink, and an outer reference electrode. preferably screen-printed in silver-silver chloride ink. The concentric design is preferable to many configurations for current distribution and potential control. A
three-electrode design can be envisaged, where there is a third counter electrode, either in the plane of the other two electrodes or opposite them.
In general, the electrodes may be connected to a read-out device by any suitable conducting contacts.
Examples include gold, copper and platinum contacts, which may be spring-loaded or otherwise biased.
Th@ filter electrode assembly is preferably a single-use disposable element. In order to ensure single use of the disposable element, there can be provided a fusible electrically conducting link which may be fused to ensure single use of the disposable element. For example, incorporated into an auxiliary electrode print can be a fine track of silver-silver chloride ink, spanning two contact pads. Before each assay, the equipment can verify that the disposable element is freshly installed and has not previously been used, and the fuse link is still intact. It can be arranged that page 7 ~313397 the equipment will then burn out the link by applying larger voltage.
The use of the fusible link has wider application. for example, a range of disposable elements can be provided with different uses, each type within the range having a fusible link with a cha~acteristic resistance. It can then be arranged that the analytical equipment can distinguish between different resistance types, and make use of this information, including to optionally display or otherwise indicate the type of disposable element which has been placed in the equipment.
More generally, the fusible link can be employed in disposable elements which do not have a filter.
Disposable elements comprising a working electrode and a reference electrode are described, for example, in EP
127958, and in "~iosensors Fundamentals and Applications~' eds Turner, Karube and Wilson, OUP, 1987.
In accordance with a further aspect of this invention, there is provided a disposable element for use in analytical equipment for an electrochemical determination, the disposable element comprising a working electrode, a reference electrode, and a fusible electrically conducting link which may be fused to ensure single use of the disposable element.
The disposable elements lacking a filter are preferably manufactured in accordance with the disclosure in EP
127958 (published 12 December 1984), which is incorporatcd hcrcin b~ rcfcrc*~o and to which the reader is now specifically referred. For example, the working electrode may incorporate a mediator and/or an enzyme.
Such disposable elements may be designed as generally planar elements, as shown in EP 127958. Printed electrodes are preferred.
page 8 However, disposable elemen~s without filter may have utility beyond mediated and like assays, and their general use in electrochemistry is envisaged by the present invention. The user of the analytical equipment does not have to set up the electrodes as before, and a greater degree of certainty and reliablity is introduced by employing a disposable element, which may be carefully manufactured as a sealed unit under controlled conditions to a consistent quality.
The disposable element, with or without filter, is advantageously packaged in a sealed packet, for example a packet made of plastics-coated aluminium which may be opened at the point of use.
The analytical equipment is preferably configured in conjunction with the disposable element such that there is only one way in which the disposable element can be received in the receiving means. The receiving means preferably comprises a generally horizontal recess accessed from above by a door, though other constructions are possible, including a horizontal slot accessed horizontally, a drawer, a vertical slot accessed vertically, and so on.
For prefeeence, the engagement of the disposable element in the analytical equipment results in automatic alignment of fluid paths and electrical connections.
The analytical equipment typically has its own pump, supplies of buffer, and other components. For automation of sample feeding and electrical measurement, microprocessor control is preferred. In order to ensure consistent results and maximised responses, the analytical equipment suitably includes a heater for incubating the microorganisms retained on the filter.
An air bubble sensor can be included, in order to detect air bubbles and thereby avoid false results. A
suitable sensor comprises two electrodes in the fluid page 9 1313397 path.
In one method in accordance with the present invention, a ce.spiratory assay is carried out, employing an artificial mediator compound. The precise mechanism by which cespiration assays function is unclear. The pcocess of respiLation in the bacterium involves oxidative degradation of a substrate, with consequent abstraction of electrons. These electrons pass between redox agents sited in the membrane of the cell, which include proteins such as the cytochromes, and small lipophilic molecules such as quinones. In aerobic respiration the electrons eventually participate in the reduction of oxygen. In anaerobic respiration, nitrate, fumarate, or other compounds can function as tecminal oxidants. It is to be assumed that artificial mediators which ace capable of becoming reduced in the presence of respiring bacteria do so by abstracting electrons fcom one or more of the redox agents in the membrane.
For a cespiration assay, the disposable element of this invention is temporarily secured in the analytical equipment. The sample is brought in to contact with the filter, for example by clowing the sample through the disposable element, thereby capturing microocganisms on the filtec. A solution of a mediator compound is then brought in to contact with the electrodes and the filter, and thus with cells captured on the filter.
The working electrode is then poised at an effective potential. If the potential is such that chemical species in the solution can be reduced or oxidised at the wocking electrode, a current will flow through the external circuit. This current flow at the electrodes can be monitored. By comparison with results obtained under standardised conditions, a quantitative assay becomes possible.
page 10 ~313397 Micro-organisms or othtr ceils which may be assayed by the use of the present invention include Gram-positive bacteria, Gram-negative bacteria, fungi, algae, cyanobacteria, yeasts, single cell cultures, and other microbes. Specific examples of cells which may be assayed include Pseudomonas fluorescens, Salmonella tYphimurium~ Listeria monocYtoqenes, and Escherichia coli.
Mediators such as ferrocene and ferrocene derivatives may be adopted in this invention. Other mediators which may be adopted include quinones, phenazine methosulphate, and especially p-benzoquinone. The mediator is preferably supplied as a solution of effective concentration.
The use of a filter in the disposable element allows microorganisms ~o be concentrated from the sample, and permits washing of the sample. For example, reductants present in orange juice (such as ascorbic acid) might interfere with a respiratory assay, but such reductants may easily be flushed away, allowing measurements to be taken on the microbes alone.
The analytical equipment of the present invention may be used for enzyme assays by addition of artificial substrates releasing an electrochsmically active moiety, and fo~ immunoassays using enzyme-labelled antibodies.
For an enzyme assay, the disposable element is temporarily secured in the analytical equipment. The sample is brought in to contact with the filter. A
solution of an enzyme substrate is then brought in to contact with the electrodes and the filter, the substrate being substrate for an enzyme of the organism. The enzyme is allowed to catalyse conversion of the substrate to a product having electroactivity different to that of the substrate. The wor~ing page 11 13~3397 electrode is poised at an effective potential and current flow at the electrodes is detected.
Using such an enzyme assay, certain species or groups of microorganisms can be identified, characterized or quantified on the basis of enzyme activity. For example, possession of alanine aminopeptidase activity is correlated in a great many cases with Gram-staining behaviour. Such enzymes further include the aminopeptidases; specifically, pyrrolidonyl aminopeptidase (pyroglutamyl aminopeptidase), E.C.
3.4.~9.3. First described from Pseudomonas fluorescens, the enzyme has been found to have widespread, although not universal, distribution among bacteria. The most comprehensive study (J Gen Microbiol (1970) 61, 9) of its distribution investigated some 2354 strains of the Enterobacteriaceae, and found 451 of these to display the enzyme activity.
In a preferred enzyme assay, a substrate is employed which on reaction in the presence of the enzyme releases a reporter group which is electrochemically active in free solution but not when coupled to the substrate.
For example, for pyrrolidonyl aminopeptidase, a suitable substrate is N,N-dimethyl-N~-pyrrolidonylphenylene-diamine. The released moiety UDon enzymatic hydrolysis is dimethylphenylenediamine, which displays an oxidation peak at +190~V vs SCE, the unreacted substrate oxidising only in the region o~ ~400mV vs SCE. Thus, by selecting a potential of about +250mV vs SCE for the assay, the two substances can be distinguished.
The detection of bacteria in the respiration assay, and the determination o~ specific bacterial enzyme activities, allows respectively quantification of total biomass and of certain groups. ~ further aspect of the present invention resides in an immunoassay format.
page 12 1313397 To this end, the presellt invention provides a method of assaying immunologically for microorganisms in a liquid sample, based on the analytical equipment and the disposable elements comprising the working electrode, the ceference electrode, and the filter. The disposable element is temporarily fixed in the analytical equipment. The sample is brought in to contact with the filter, followed by a solution of an enzyme-labelled antibody, the antibody (monoclonal or polyclonal) being one which immunoreacts with a microorganism to be determined. The labelled antibody binds to immobilised microbial antigens on microorganisms trapped at the filter. Excess unbound reagent can be removed by a wash procedure, and the enzyme label associated with the filter can be quantitated. To this end, a solution of a substrate is brought in to contact with the electrodes and the filter, being substrate for the enzyme of the en~yme-labelled antibody. The labelling enzyme is allowed to catalyse conversion of the substrate to a product of electroactivity different to that of the substrate. By poising the working electrode at an effective potential, current flow at the electrodes can be monitored. The magnitude of the current produced by oxidation (or reduction) of the product at the working electrode can be related to the microbial loading on the filter.
This method allows discrimination of different strains within the same species, or of different species or different serotypes within the same genera. For example, detection of E. coli is possible using a mouse anti E. coli monoclonal antibody and anti-mouse alkaline phosphatase conjugate, the filter being preferably blocked beforehand to reduce non-specific binding reactions. A mouse anti E. coli monoclonal antibody labelled with alkaline phosphatase represents another suitable reagent.
In general, for methods of this invention, it is preferred to minimise background currents, in view of the sensitivity of the assay. The true zero response is closely defined, in order to discern small signals above the response level. One method is to use an experimental protocol in which a blank measurement is made at the, start of the procedure, after which sample is introduced, the reaction performed, and a second current meas*urement made in which the results of the reaction are assayed. The response of the instrument to the sample is then the difference between the two measurements.
The present invention will now be further illustrated with respect to the accompanying drawings, in which:
Figure 1 shows an exploded view of a disposable element according to the present invention;
Figure 2a, 2b and 2c respectively show a view from above, a vertical cross-section, and a printed base plate for another disposable element according to the invention;
Figure 3 shows a continuous tape providing multiple disposable elements of this invention; and Figure 4 shows a perspective view in open configuration of analytical equipment according to the present invention:
Figure 5 shows stages in an immunoassay of the present invention; and Figure 6 shows graphs of measurements taken on an pyrrolidonyl aminopeptidase system of Example 7.
Example 1 Dis~osable Element Figure 1 is an exploded view of one embodiment of a disposable element of this invention. Considered from the bottom of the figure, the element comprises a base plate 10 with central aperture 11 and printed working electrode 12, reference electrode 13, fusible link 14 and electrical contacts 15; an adhesive layer 16; a filter membrane 1.7; a backing mesh 18; an impermeable centre spot 19; an adhesive ring 20; a diaphragm 21 with counter electrode 22; an adhesive layer 23; and a top cover 24 with central aperture 25. Coaxial apertures ~6 extend through to the electrical contacts 15 on the base plate, and apertures 27 through to the counter electrode.
When sample is pumped through the disposable element, the diaphragm 21 flexes away from the filter 17 to allow liquid flow fully across the filter. When pumping ceases, the diaphragm relaxes and the filter is then held in close contact with the electrodes.
Example 2 Disposable Element Figure 2 illustrates the currently preferred construction for a disposable element of this invention. A base plate 30 of pvc serves as the electrode support. There are two concentric electrodes comprising a working electrode 31 screen-printed in organic-based carbon ink, and an outer reference electrode 32 screen-printed in silver/silver chloride - 14a -page 15 ~3~3397 ink, and including a fi~sible link 40. The base plate has one central aperture 33 for liquid ingress. An upper sheet 34 i6 formed to hold a filter disc 35 of gla6s fibee in place. A two-step recess is formed in this sheet, so that when the element is assembled, the filtec disc i.s crushed slightly around its edge, discouraging leakage of fluid round the edge o~ the filter.
Outlet of fluid is through eight apertures 3~ in a circle: this ensures that the whole extent of the filter within the second step of the recess is used for filtration. To further ensure the maximum possible flow rate a dimpled texture with dimples 37 is formed on the upper sheet within the eight outlet apertures. This holds the filter away from the back wall of the disposable when under pressure. Three apertures 3~ in the upper sheet expose the electrode and fuse contacts 39. Although pvc is used for both halves of the disposable element, other plastics such as polycarbonate could be used. While the upper sheet of pvc is thermoformed into shape at present, this component could equally be injection-moulded in polystyrene, or made in other ways.
After assembly of the two sheets of pvc with filter disc, the two halves are adhered together with transfer adhesive, or alternatively using thin (<5~m) double-sided tape or liquid glue printed, sprayed or rollered. The disposable is then punched out into its final shape, which is essentially rectangular, with rounded corners and a notch on the left hand side ensuring cor~ect insertion into the housing shown in figure 4.
In a further embodiment shown in Figure 3 of the disposable element, the disposable elements can be page 16 ~3~3397 provided as a continuvus ~ape, as illustrated in the figure in partially exploded form, with a continuous bottom ribbon 46 carrying the electrodes, a continous filter ribbon 47, and a continuous embossed upper ribbon 48. Such a tape is particularly useful with analytical equipment having an automated step-wise feed for sequentially feeding the elements in turn in to position for repeated assays.
ExamDle 3 AnalYtical EquiPment The views Oe figure 4 generally illustrate the analytical equipment 50 in accordance with this invention. Within a housing 51 is a generally horizontal recess 5Z for receiving a disposable element 53, and means ~not shown) for fluid handling, temperature control, and electronic hardware. The equipment is designed to make automatic electrical and fluid connections to the disposable element placed in the recess when the lid 54 of the housing is latched shut.
The measurement system includes a thermostatted heater, a fluid handling system with a pump, switching valves, and air-bubble sensor, a potentiostat for measuring current transients, and a single card computer, a~sociated intereaces and micro disc drive. The unit carr.ies out the following functions;
i) maintains the ~ilter cell at a preset temperature.
ii) pumps through the cell measured quantities of sample and reagents.
1~13397 page 17 iii) applies a potentiai and measures the resulting integrated current response.
iv) calculates the microbial concentration.
v) inputs data from the user such as batch numbers, sample data, and outputs the result of ~he assay.
vi) ~tores the reslllts and data and printed output.
vii) checks at all stages for errors such as end of reagent, previously used cell or fluid blockage, and peovides interlocks to prevent mishandlin~.
The analytical equipment of Figure 4 with disposable elements of Figure 2 can be employed, for instance, in a respiratory a~say, for which the following protocols are appropriate:
A. Simple protocol 1. Introduce sample.
Accurate and rapid determination of microbial activity is essential in many areas, including pollution control; ~uality assurance in the food, drink and drugs industries; and clinical analysis of bodily fluids and other medical samples.
For a long time, the standard method for the enumeration of bacteria has been an agar plate count. This method has many disadvantages, especially the time needed to obtain results~
Even with the fastest growth, 18 hours is needed for visible colony formation, and then there is the task of counting the colonies.
There have been proposals to employ bioelectrochemical cells or fuel cells for assaying of microbiological samples. For example, amperometric determination of viable cell numbers based on sensing microbial respiration is described in Appl Microbiol Biotechnol (1981) 12, 97; the use of a microbial fuel cell for the rapid enumeration of bacteria is described in Appl Microbiol Biotechnol (1988) 28, ~6; and an investigation of a simple amperometric electrode system to rapidly quantify and detect bacteria is described in J Appl ~313397 Bacteriol (1989) 66, 49. Further aspects of amperometric bioassay systems are described in EP 190470 and 238322, and GB 2181451 and 2181558, among other examples. Some of these systems employ a filter to capture microbial cells at the electrodes, after which the determination is effected.
The present invention provides analytical equipment for a bioelectrochemical determination of microorganisms or other cells in a liquid sample using a working electrode and a reference electrode. The working electrode, the reference electrode, and a filter for retention of solids in the vicinity of the electrodes are provided as a disposable element. The analytical equipment has receiving mea~s for releasably receiving the disposable element.
Since the electrodes and filter are provided as a disposable element, the user of the analytical equipment does not have to set up the electrodes and arrange the filter. A greater degree of certainty and reliablity is introduced by employing the disposable element, which may be carefully manufactured as a sealed unit under controlled conditions to a consistent quality.
The disposable elements themselves are part of this invention, and in further aspects, the present invention provides methods of assay for microorganisms or other cells which methods employ the disposable elements.
The disposable element in conjunction with the associated analytical equipment is suitably designed for page 3 ~313397 through-flow use to ~eap any cells in the sample, e~fecting concentration and allowing washing. At p~esent a generally planar disposable element is preferred, especially for use with the electrodes and filter extending generally horizontally, and with flow through the element being generally vertical.
The filter of the disposable element may be interposed between opposed electrodes, or in alternative constructions, the filter can be upstream of the electrodes. The choice of filter material depends on three main criteria: good retention of biological cells (90% or better); adequate flow rate at a given pressure:
and reasonable resistance to blockage. The last two criteria affect the volume of a particular sample that can be introduced and hence the degree of concentration obtainable .
Particularly suitable filters are depth filters, especially glass ~ibre filters (for example, as manufactured by Whatman or Millipore). Other filters can be employed, such as membrane filters, charge-modified filters, and so on. Alternative forms of filters might be adopted, including capture matrices such as antibodies or lectins immobilised on beads.
The filter may be housed in a housing made from two halves fitted together. These two halves can be made in an injection moulding process. Furthermore, meshes can be employed to encourage the desired flow and distribution of liquid through the filter.
The wo~king electrode may be based on known materials.
It is possible to use noble metals such as gold or platinum, but it is generally preferred to use less expensive materials for the manufacture of disposable devices. A suitable material may be gLaphite felt lfor example, RVG2000 Le Carbone). However, graphite felt tends to provide high electrical resistance, and in a page 4 1313397 prefereed aspect of this invention, it has been found that good results are available from the use of printed carbon electrodes. In a particularly preferred aspect, one or more of the electrodes is screen printed.
The reference electrode typically comprises silver and silvec chloride (Ag/AgCl), or mercury and mercury chloride (saturated calomel electrode, SCE). Such systems have known, absolute electrode potentials in aqueous media. It is preferred to use the reference electrode alone to complete the external circuit, particularly when currents are small -6 or less). Especially preferred is a printed silver/silver chloride reference electrode.
Since the potential of the reference electrode can drift as current passes, it is possible to provide a counter electrode through which the bulk of the current can be directed. Suitable materials for counter electrodes include platinum, gold or silver. Where a counter electrode is used, it is sufficient that the reference electrode has enough surface area to establish the reference potential.
Screen-printed electrodes present a number of advantages: there is more scope for optimising electrode behaviour and configuration, and a close proximity of working and reference electrodes can be achieved. The resistances are lower than with graphite felt, and it is considerably easier to make contacts to the electrodes. The response of printed electrodes to bacteria are of the same order as those obtained with graphite felt, but a little lower. However, this result i6 compensated for by better and more controllable background currents.
The reference and/or working electrode and/or counter electrode is suitably formed by printing or otherwise 13~3~97 page S
coating onto an ineet subs~rate, such as a fibre (for instance glass fibre) matrix or plastics (for instance polyvinyl chloride, "pvc") substrate. Permeability of the electrode can be an advantage, but it may be solid, provided that fluid can pass across its surface. When the electrode serves no filtering function it is equally possible to use a solid electrode with one or more apertures for passage of liquid, or to use a network or mateix allowing free passage of liquid through all parts of the electrode.
In one embodiment, the working electrode is carbon felt, laid over a filter, with a matrix reference electrode positioned opposite the working electrode. The whole is placed in a housing and the sample is fed in through an entry port. Thi~ diffuses across the filter allowing the surface areas of both electrodes to be effectively used. In practice, a buffer will generally be passed through in both direction to purge any air present, be~ore the sample is introduced, again, in eithee direction. This is then usefully followed by washing with buffer and introduction of compounds acting as mediators. as required.
In an alternative embodiment, the electrode through which the sample is introduced has a single aperture preferably in the centre, while an opposite electrode allows escape of fluid about its periphery, preferably through more than one aperture, for example eight apertures.
In another embodiment, a working electrode of carbon printed ink i8 interdigitated with a reference electrode printed in si.lver/silvee chloride ink. For example a star-shape electrode interdigitates with the other electrode. The close proximity of reference and working electrodes allows qood control of the potential at the working electrode surface. A counter electrode 13~3~97 page 6 can be provided by a disc printed in silver ink. The electrodes are suitably printed onto 0.5mm thick pvc, and cut into discs. Apertures punched in the discs allow liquid flow: a central aperture in the working/reference electrode disc and eight peripheral apertures in the other disc being suitable. The discs can then be assembled in a filter electrode holder on either side of a glass-fibre filter disc, to give a disposable element.
In a yet further embodiment, the disposable element comprises a pvc or other plastics substrate with two concentric electrodes comprising a working electrode, preferably scceen-printed in organic-based carbon ink, and an outer reference electrode. preferably screen-printed in silver-silver chloride ink. The concentric design is preferable to many configurations for current distribution and potential control. A
three-electrode design can be envisaged, where there is a third counter electrode, either in the plane of the other two electrodes or opposite them.
In general, the electrodes may be connected to a read-out device by any suitable conducting contacts.
Examples include gold, copper and platinum contacts, which may be spring-loaded or otherwise biased.
Th@ filter electrode assembly is preferably a single-use disposable element. In order to ensure single use of the disposable element, there can be provided a fusible electrically conducting link which may be fused to ensure single use of the disposable element. For example, incorporated into an auxiliary electrode print can be a fine track of silver-silver chloride ink, spanning two contact pads. Before each assay, the equipment can verify that the disposable element is freshly installed and has not previously been used, and the fuse link is still intact. It can be arranged that page 7 ~313397 the equipment will then burn out the link by applying larger voltage.
The use of the fusible link has wider application. for example, a range of disposable elements can be provided with different uses, each type within the range having a fusible link with a cha~acteristic resistance. It can then be arranged that the analytical equipment can distinguish between different resistance types, and make use of this information, including to optionally display or otherwise indicate the type of disposable element which has been placed in the equipment.
More generally, the fusible link can be employed in disposable elements which do not have a filter.
Disposable elements comprising a working electrode and a reference electrode are described, for example, in EP
127958, and in "~iosensors Fundamentals and Applications~' eds Turner, Karube and Wilson, OUP, 1987.
In accordance with a further aspect of this invention, there is provided a disposable element for use in analytical equipment for an electrochemical determination, the disposable element comprising a working electrode, a reference electrode, and a fusible electrically conducting link which may be fused to ensure single use of the disposable element.
The disposable elements lacking a filter are preferably manufactured in accordance with the disclosure in EP
127958 (published 12 December 1984), which is incorporatcd hcrcin b~ rcfcrc*~o and to which the reader is now specifically referred. For example, the working electrode may incorporate a mediator and/or an enzyme.
Such disposable elements may be designed as generally planar elements, as shown in EP 127958. Printed electrodes are preferred.
page 8 However, disposable elemen~s without filter may have utility beyond mediated and like assays, and their general use in electrochemistry is envisaged by the present invention. The user of the analytical equipment does not have to set up the electrodes as before, and a greater degree of certainty and reliablity is introduced by employing a disposable element, which may be carefully manufactured as a sealed unit under controlled conditions to a consistent quality.
The disposable element, with or without filter, is advantageously packaged in a sealed packet, for example a packet made of plastics-coated aluminium which may be opened at the point of use.
The analytical equipment is preferably configured in conjunction with the disposable element such that there is only one way in which the disposable element can be received in the receiving means. The receiving means preferably comprises a generally horizontal recess accessed from above by a door, though other constructions are possible, including a horizontal slot accessed horizontally, a drawer, a vertical slot accessed vertically, and so on.
For prefeeence, the engagement of the disposable element in the analytical equipment results in automatic alignment of fluid paths and electrical connections.
The analytical equipment typically has its own pump, supplies of buffer, and other components. For automation of sample feeding and electrical measurement, microprocessor control is preferred. In order to ensure consistent results and maximised responses, the analytical equipment suitably includes a heater for incubating the microorganisms retained on the filter.
An air bubble sensor can be included, in order to detect air bubbles and thereby avoid false results. A
suitable sensor comprises two electrodes in the fluid page 9 1313397 path.
In one method in accordance with the present invention, a ce.spiratory assay is carried out, employing an artificial mediator compound. The precise mechanism by which cespiration assays function is unclear. The pcocess of respiLation in the bacterium involves oxidative degradation of a substrate, with consequent abstraction of electrons. These electrons pass between redox agents sited in the membrane of the cell, which include proteins such as the cytochromes, and small lipophilic molecules such as quinones. In aerobic respiration the electrons eventually participate in the reduction of oxygen. In anaerobic respiration, nitrate, fumarate, or other compounds can function as tecminal oxidants. It is to be assumed that artificial mediators which ace capable of becoming reduced in the presence of respiring bacteria do so by abstracting electrons fcom one or more of the redox agents in the membrane.
For a cespiration assay, the disposable element of this invention is temporarily secured in the analytical equipment. The sample is brought in to contact with the filter, for example by clowing the sample through the disposable element, thereby capturing microocganisms on the filtec. A solution of a mediator compound is then brought in to contact with the electrodes and the filter, and thus with cells captured on the filter.
The working electrode is then poised at an effective potential. If the potential is such that chemical species in the solution can be reduced or oxidised at the wocking electrode, a current will flow through the external circuit. This current flow at the electrodes can be monitored. By comparison with results obtained under standardised conditions, a quantitative assay becomes possible.
page 10 ~313397 Micro-organisms or othtr ceils which may be assayed by the use of the present invention include Gram-positive bacteria, Gram-negative bacteria, fungi, algae, cyanobacteria, yeasts, single cell cultures, and other microbes. Specific examples of cells which may be assayed include Pseudomonas fluorescens, Salmonella tYphimurium~ Listeria monocYtoqenes, and Escherichia coli.
Mediators such as ferrocene and ferrocene derivatives may be adopted in this invention. Other mediators which may be adopted include quinones, phenazine methosulphate, and especially p-benzoquinone. The mediator is preferably supplied as a solution of effective concentration.
The use of a filter in the disposable element allows microorganisms ~o be concentrated from the sample, and permits washing of the sample. For example, reductants present in orange juice (such as ascorbic acid) might interfere with a respiratory assay, but such reductants may easily be flushed away, allowing measurements to be taken on the microbes alone.
The analytical equipment of the present invention may be used for enzyme assays by addition of artificial substrates releasing an electrochsmically active moiety, and fo~ immunoassays using enzyme-labelled antibodies.
For an enzyme assay, the disposable element is temporarily secured in the analytical equipment. The sample is brought in to contact with the filter. A
solution of an enzyme substrate is then brought in to contact with the electrodes and the filter, the substrate being substrate for an enzyme of the organism. The enzyme is allowed to catalyse conversion of the substrate to a product having electroactivity different to that of the substrate. The wor~ing page 11 13~3397 electrode is poised at an effective potential and current flow at the electrodes is detected.
Using such an enzyme assay, certain species or groups of microorganisms can be identified, characterized or quantified on the basis of enzyme activity. For example, possession of alanine aminopeptidase activity is correlated in a great many cases with Gram-staining behaviour. Such enzymes further include the aminopeptidases; specifically, pyrrolidonyl aminopeptidase (pyroglutamyl aminopeptidase), E.C.
3.4.~9.3. First described from Pseudomonas fluorescens, the enzyme has been found to have widespread, although not universal, distribution among bacteria. The most comprehensive study (J Gen Microbiol (1970) 61, 9) of its distribution investigated some 2354 strains of the Enterobacteriaceae, and found 451 of these to display the enzyme activity.
In a preferred enzyme assay, a substrate is employed which on reaction in the presence of the enzyme releases a reporter group which is electrochemically active in free solution but not when coupled to the substrate.
For example, for pyrrolidonyl aminopeptidase, a suitable substrate is N,N-dimethyl-N~-pyrrolidonylphenylene-diamine. The released moiety UDon enzymatic hydrolysis is dimethylphenylenediamine, which displays an oxidation peak at +190~V vs SCE, the unreacted substrate oxidising only in the region o~ ~400mV vs SCE. Thus, by selecting a potential of about +250mV vs SCE for the assay, the two substances can be distinguished.
The detection of bacteria in the respiration assay, and the determination o~ specific bacterial enzyme activities, allows respectively quantification of total biomass and of certain groups. ~ further aspect of the present invention resides in an immunoassay format.
page 12 1313397 To this end, the presellt invention provides a method of assaying immunologically for microorganisms in a liquid sample, based on the analytical equipment and the disposable elements comprising the working electrode, the ceference electrode, and the filter. The disposable element is temporarily fixed in the analytical equipment. The sample is brought in to contact with the filter, followed by a solution of an enzyme-labelled antibody, the antibody (monoclonal or polyclonal) being one which immunoreacts with a microorganism to be determined. The labelled antibody binds to immobilised microbial antigens on microorganisms trapped at the filter. Excess unbound reagent can be removed by a wash procedure, and the enzyme label associated with the filter can be quantitated. To this end, a solution of a substrate is brought in to contact with the electrodes and the filter, being substrate for the enzyme of the en~yme-labelled antibody. The labelling enzyme is allowed to catalyse conversion of the substrate to a product of electroactivity different to that of the substrate. By poising the working electrode at an effective potential, current flow at the electrodes can be monitored. The magnitude of the current produced by oxidation (or reduction) of the product at the working electrode can be related to the microbial loading on the filter.
This method allows discrimination of different strains within the same species, or of different species or different serotypes within the same genera. For example, detection of E. coli is possible using a mouse anti E. coli monoclonal antibody and anti-mouse alkaline phosphatase conjugate, the filter being preferably blocked beforehand to reduce non-specific binding reactions. A mouse anti E. coli monoclonal antibody labelled with alkaline phosphatase represents another suitable reagent.
In general, for methods of this invention, it is preferred to minimise background currents, in view of the sensitivity of the assay. The true zero response is closely defined, in order to discern small signals above the response level. One method is to use an experimental protocol in which a blank measurement is made at the, start of the procedure, after which sample is introduced, the reaction performed, and a second current meas*urement made in which the results of the reaction are assayed. The response of the instrument to the sample is then the difference between the two measurements.
The present invention will now be further illustrated with respect to the accompanying drawings, in which:
Figure 1 shows an exploded view of a disposable element according to the present invention;
Figure 2a, 2b and 2c respectively show a view from above, a vertical cross-section, and a printed base plate for another disposable element according to the invention;
Figure 3 shows a continuous tape providing multiple disposable elements of this invention; and Figure 4 shows a perspective view in open configuration of analytical equipment according to the present invention:
Figure 5 shows stages in an immunoassay of the present invention; and Figure 6 shows graphs of measurements taken on an pyrrolidonyl aminopeptidase system of Example 7.
Example 1 Dis~osable Element Figure 1 is an exploded view of one embodiment of a disposable element of this invention. Considered from the bottom of the figure, the element comprises a base plate 10 with central aperture 11 and printed working electrode 12, reference electrode 13, fusible link 14 and electrical contacts 15; an adhesive layer 16; a filter membrane 1.7; a backing mesh 18; an impermeable centre spot 19; an adhesive ring 20; a diaphragm 21 with counter electrode 22; an adhesive layer 23; and a top cover 24 with central aperture 25. Coaxial apertures ~6 extend through to the electrical contacts 15 on the base plate, and apertures 27 through to the counter electrode.
When sample is pumped through the disposable element, the diaphragm 21 flexes away from the filter 17 to allow liquid flow fully across the filter. When pumping ceases, the diaphragm relaxes and the filter is then held in close contact with the electrodes.
Example 2 Disposable Element Figure 2 illustrates the currently preferred construction for a disposable element of this invention. A base plate 30 of pvc serves as the electrode support. There are two concentric electrodes comprising a working electrode 31 screen-printed in organic-based carbon ink, and an outer reference electrode 32 screen-printed in silver/silver chloride - 14a -page 15 ~3~3397 ink, and including a fi~sible link 40. The base plate has one central aperture 33 for liquid ingress. An upper sheet 34 i6 formed to hold a filter disc 35 of gla6s fibee in place. A two-step recess is formed in this sheet, so that when the element is assembled, the filtec disc i.s crushed slightly around its edge, discouraging leakage of fluid round the edge o~ the filter.
Outlet of fluid is through eight apertures 3~ in a circle: this ensures that the whole extent of the filter within the second step of the recess is used for filtration. To further ensure the maximum possible flow rate a dimpled texture with dimples 37 is formed on the upper sheet within the eight outlet apertures. This holds the filter away from the back wall of the disposable when under pressure. Three apertures 3~ in the upper sheet expose the electrode and fuse contacts 39. Although pvc is used for both halves of the disposable element, other plastics such as polycarbonate could be used. While the upper sheet of pvc is thermoformed into shape at present, this component could equally be injection-moulded in polystyrene, or made in other ways.
After assembly of the two sheets of pvc with filter disc, the two halves are adhered together with transfer adhesive, or alternatively using thin (<5~m) double-sided tape or liquid glue printed, sprayed or rollered. The disposable is then punched out into its final shape, which is essentially rectangular, with rounded corners and a notch on the left hand side ensuring cor~ect insertion into the housing shown in figure 4.
In a further embodiment shown in Figure 3 of the disposable element, the disposable elements can be page 16 ~3~3397 provided as a continuvus ~ape, as illustrated in the figure in partially exploded form, with a continuous bottom ribbon 46 carrying the electrodes, a continous filter ribbon 47, and a continuous embossed upper ribbon 48. Such a tape is particularly useful with analytical equipment having an automated step-wise feed for sequentially feeding the elements in turn in to position for repeated assays.
ExamDle 3 AnalYtical EquiPment The views Oe figure 4 generally illustrate the analytical equipment 50 in accordance with this invention. Within a housing 51 is a generally horizontal recess 5Z for receiving a disposable element 53, and means ~not shown) for fluid handling, temperature control, and electronic hardware. The equipment is designed to make automatic electrical and fluid connections to the disposable element placed in the recess when the lid 54 of the housing is latched shut.
The measurement system includes a thermostatted heater, a fluid handling system with a pump, switching valves, and air-bubble sensor, a potentiostat for measuring current transients, and a single card computer, a~sociated intereaces and micro disc drive. The unit carr.ies out the following functions;
i) maintains the ~ilter cell at a preset temperature.
ii) pumps through the cell measured quantities of sample and reagents.
1~13397 page 17 iii) applies a potentiai and measures the resulting integrated current response.
iv) calculates the microbial concentration.
v) inputs data from the user such as batch numbers, sample data, and outputs the result of ~he assay.
vi) ~tores the reslllts and data and printed output.
vii) checks at all stages for errors such as end of reagent, previously used cell or fluid blockage, and peovides interlocks to prevent mishandlin~.
The analytical equipment of Figure 4 with disposable elements of Figure 2 can be employed, for instance, in a respiratory a~say, for which the following protocols are appropriate:
A. Simple protocol 1. Introduce sample.
2. Wash with buffer/electcolyte.
3. Introduce mediator/buffer/electrolyte.
4. Incubate for specified period at specified temperature.
5. Apply potential and measure current.
B. Protocol with lower-value calibration l. Flush system with mediator/buffer/electrolyte.
Wait for specified temperature.
2. Apply potential, measure current. Record as null value.
3. Wash with buffer/electrolyte.
4. Continue from (A1) above.
page 18 131339~
ExamPle 4 An ImmunoassaY
Refercing to Figure 5, sample is pass0d through the disposable element of figure 2, capturing bacteria 61 on the filter 60. Soluble components in the sample are removed by a wash reagent, which is followed by a solution of antibody-en~yme conjugate 62. The antibody used is designed to bind specifically with a particular genus, species (or serotype) of microorganism and i6 covalently coupled to an enzyme reporter group to facilitate detection. Following a simple wash step to remove exceæs unbound reagent, the enzyme label now intimately associated with the filter is quantified with an appropriate substrate 63. The enzyme (such as alkaline phosphate) converts substrate to an electroactive product, in known manner, whose concentration is determined by oxidationtreduction at the electrode surface 64.
The resultant current is then in direct proportion to the number of bacteria trapped in the filter. The immunoassay format thus not only allows identification of specific bacteria (by virtue of the antigen-dntibody interaction), but also direct enumeration of the species concerned.
Example 5 ~ respiratory~assaY
Following insertion of the disposable element o~ Figure 2 in to the housing of Figure 4, 10 ~1 of phosphate/chloride buffec (lOOmM sodium phosphate, lOOmM
sodium chloride, pH 6.8, containg lOmM glucose) was pumped in an upwacd dicection. Sample was then 1313:~97 page 19 introduced, followed by buffer to wash medium components from the filtee. The assembly was next flooded with the buffee solution, containing ~.25mM ~-benzoquinone. The whole was ~hen incubated at 37C, typically for 10 minutes, after which time a potential of +400mV V8 Aq/AgCl was applied to the working electrode and the current recorded.
The fol.lowing table shows the responses (~A at t = 30 seconds, corrected for background) obtained for four different microorganisms at various dilutions in appeopriate media.
Microrganism cfu/ml response Bacillus cereus 1 x 10 4.2 ~NCFB 1771) 1 x 10 0.5 Pseudomonas 2 x 10 8.0 fluorescens 2 x 103 1.0 NCTC 10038) ~scherichia 1.3 x 10 10.0 coli 1.3 x 10 1.6 (MM 522) ~.3 x 10 0.6 Serratia 7.7 x 108 23.6 marcescens 7.7 x 106 4.5 (ATCC 14756) 7.7 x 10 1.0 Example 6 Screenin~ of Bacteria The response of a benzoquinone respiration assay with several species of bacteria was tested, and the relative responses of the different bacteria measured. The page Z0 ~313397 reaction was carr;ed out in lOOmM sodium phosphate buf~er, pH6.8, containing lOOmM sodium chloride.
Glucose was included at lOmM, and P-benzoquinone was present at l.25mM (p-benzoquinone was obtained from BDH, and recrystallised from 40-60 petroleum ether).
Bacteria were grown in either nutrient broth (Gibco BRL~
or in yeast glucose beoth (nutrient broth plus 0.3% w/v yeast extract: 0.5% (w/v) glucose, pH6.8) but were washed and resuspended in lOOmM sodium phosphate pH6.8;
lOOmM sodium chloride; lOmM glucose prior to as6ay.
Bacteria were either added directly to the cell along with mediator solution, and incubated at known temperature for a given time, or the incubation was performed remotely from the cell and the solution transferred to the cell for measurement. The currents were normalised for cell numbers (as estimated by standard plate count) and expressed relative to the response of E. coli NM522 taken as 100. The results are presented in the following table.
Table F~esPonse Bacillus badius ATCC 14574 50 Bacillus cereus NCFB 1771 3098 Bacillus sPhaericus ATCC 14577 375 Bacillu6 subtilis NCFB 17692159 ~scherichia coli NM5~2 (100) Pseudomonas fluorescens ATCC 25289 4.5 Salmonella tYPhimurium ATCC 13311 50 Data for Bacillus cereus and Bacillus subtilis are included in the table, but the plate-count results for these organisms were surprisingly low (hence the large normalised re~ponses). There is scatter within the data, but the assay detected all the species of bacteria page 21 ~313397 tested and there was no corLelation with species or Gram-staininq behavioue.
ExamDle 7 Enzyme activity was assayed using both mammalian pyrrolidonyl aminopeptidase and the enzyme naturally present in Pseudomonas fluorescens ATCC 25289. A
calibration cueve for the assay of the mammalian enzyme is peesented in Figure ~(a), using 50mM Tris.HC1, pH
8.3, 25C, lOOmM Na~l, lmM substrate. A calibration curve for Ps. fluorescens is presented in Figuee 6(b), using substrate at 2mM in buffer as before. A good linear response with bacterial cell numbers was observed. In the case of Ps. fluorescens, the enzyme activity was found to be localised within the cells eather than secreted into the medium.
Further Examples Although the invention has been illustrated with re~erence to disposable elements which have a filtee, the invention also embraces disposable elements comprising a eeference electrode, working electrode, and fusible link. Such electrodes may be manufactured for example by screen printing a substrate as if to make an disposable element in accordance with EP 127958 but furthee including a fusible link.
B. Protocol with lower-value calibration l. Flush system with mediator/buffer/electrolyte.
Wait for specified temperature.
2. Apply potential, measure current. Record as null value.
3. Wash with buffer/electrolyte.
4. Continue from (A1) above.
page 18 131339~
ExamPle 4 An ImmunoassaY
Refercing to Figure 5, sample is pass0d through the disposable element of figure 2, capturing bacteria 61 on the filter 60. Soluble components in the sample are removed by a wash reagent, which is followed by a solution of antibody-en~yme conjugate 62. The antibody used is designed to bind specifically with a particular genus, species (or serotype) of microorganism and i6 covalently coupled to an enzyme reporter group to facilitate detection. Following a simple wash step to remove exceæs unbound reagent, the enzyme label now intimately associated with the filter is quantified with an appropriate substrate 63. The enzyme (such as alkaline phosphate) converts substrate to an electroactive product, in known manner, whose concentration is determined by oxidationtreduction at the electrode surface 64.
The resultant current is then in direct proportion to the number of bacteria trapped in the filter. The immunoassay format thus not only allows identification of specific bacteria (by virtue of the antigen-dntibody interaction), but also direct enumeration of the species concerned.
Example 5 ~ respiratory~assaY
Following insertion of the disposable element o~ Figure 2 in to the housing of Figure 4, 10 ~1 of phosphate/chloride buffec (lOOmM sodium phosphate, lOOmM
sodium chloride, pH 6.8, containg lOmM glucose) was pumped in an upwacd dicection. Sample was then 1313:~97 page 19 introduced, followed by buffer to wash medium components from the filtee. The assembly was next flooded with the buffee solution, containing ~.25mM ~-benzoquinone. The whole was ~hen incubated at 37C, typically for 10 minutes, after which time a potential of +400mV V8 Aq/AgCl was applied to the working electrode and the current recorded.
The fol.lowing table shows the responses (~A at t = 30 seconds, corrected for background) obtained for four different microorganisms at various dilutions in appeopriate media.
Microrganism cfu/ml response Bacillus cereus 1 x 10 4.2 ~NCFB 1771) 1 x 10 0.5 Pseudomonas 2 x 10 8.0 fluorescens 2 x 103 1.0 NCTC 10038) ~scherichia 1.3 x 10 10.0 coli 1.3 x 10 1.6 (MM 522) ~.3 x 10 0.6 Serratia 7.7 x 108 23.6 marcescens 7.7 x 106 4.5 (ATCC 14756) 7.7 x 10 1.0 Example 6 Screenin~ of Bacteria The response of a benzoquinone respiration assay with several species of bacteria was tested, and the relative responses of the different bacteria measured. The page Z0 ~313397 reaction was carr;ed out in lOOmM sodium phosphate buf~er, pH6.8, containing lOOmM sodium chloride.
Glucose was included at lOmM, and P-benzoquinone was present at l.25mM (p-benzoquinone was obtained from BDH, and recrystallised from 40-60 petroleum ether).
Bacteria were grown in either nutrient broth (Gibco BRL~
or in yeast glucose beoth (nutrient broth plus 0.3% w/v yeast extract: 0.5% (w/v) glucose, pH6.8) but were washed and resuspended in lOOmM sodium phosphate pH6.8;
lOOmM sodium chloride; lOmM glucose prior to as6ay.
Bacteria were either added directly to the cell along with mediator solution, and incubated at known temperature for a given time, or the incubation was performed remotely from the cell and the solution transferred to the cell for measurement. The currents were normalised for cell numbers (as estimated by standard plate count) and expressed relative to the response of E. coli NM522 taken as 100. The results are presented in the following table.
Table F~esPonse Bacillus badius ATCC 14574 50 Bacillus cereus NCFB 1771 3098 Bacillus sPhaericus ATCC 14577 375 Bacillu6 subtilis NCFB 17692159 ~scherichia coli NM5~2 (100) Pseudomonas fluorescens ATCC 25289 4.5 Salmonella tYPhimurium ATCC 13311 50 Data for Bacillus cereus and Bacillus subtilis are included in the table, but the plate-count results for these organisms were surprisingly low (hence the large normalised re~ponses). There is scatter within the data, but the assay detected all the species of bacteria page 21 ~313397 tested and there was no corLelation with species or Gram-staininq behavioue.
ExamDle 7 Enzyme activity was assayed using both mammalian pyrrolidonyl aminopeptidase and the enzyme naturally present in Pseudomonas fluorescens ATCC 25289. A
calibration cueve for the assay of the mammalian enzyme is peesented in Figure ~(a), using 50mM Tris.HC1, pH
8.3, 25C, lOOmM Na~l, lmM substrate. A calibration curve for Ps. fluorescens is presented in Figuee 6(b), using substrate at 2mM in buffer as before. A good linear response with bacterial cell numbers was observed. In the case of Ps. fluorescens, the enzyme activity was found to be localised within the cells eather than secreted into the medium.
Further Examples Although the invention has been illustrated with re~erence to disposable elements which have a filtee, the invention also embraces disposable elements comprising a eeference electrode, working electrode, and fusible link. Such electrodes may be manufactured for example by screen printing a substrate as if to make an disposable element in accordance with EP 127958 but furthee including a fusible link.
Claims (16)
1. A disposable element for use in analytical equipment for bioelectrochemical determination, the disposable element comprising a base plate having an aperture for flow of liquid through said element, a working electrode coated on a face of said base plate, a reference electrode coated on said face of said base plate, and a filter in contact with said electrodes for retention of solids in the vicinity of said electrodes for determination.
2. A disposable element according to claim 1, which is a single-use disposable element.
3. A disposable element according to claim 2, which has a fusible electrically conducting link which may be fused to ensure single use of the disposable element.
4. A disposable element according to claim 1, wherein the filter is a depth filter.
5. A disposable element according to claim 1, wherein the disposable element further comprises a counter electrode.
6. A disposable element according to claim 1, wherein at least one of the electrodes is printed.
7. A disposable element according to claim 6, wherein the working electrode and the reference electrode are printed on the same surface.
8. Analytical equipment for bioelectrochemical determination using a working electrode coated on a face of a base plate having an aperture to allow flow of liquid past said electrode and a reference electrode coated on said face of said base plate, wherein said base plate, working electrode, said reference electrode, and a filter in contact with said electrodes for retention of solids in the vicinity of the electrodes, are provided as a disposable element, and wherein the analytical equipment has receiving means for releasably receiving the disposable element.
9. Analytical equipment for a bioelectrochemical determination using a working electrode coated on a face of a base plate having an aperture to allow flow of liquid past said electrode and a reference electrode coated on said face of said base plate, wherein said base plate, working electrode, said reference electrode and a filter in contact with said base plate for retention of solids in the vicinity of the electrodes, are provided as a disposable element, and wherein the analytical equipment has receiving means for releasably receiving the disposable element, wherein the disposable element is as defined in any one of claims 1 to 7.
10. Analytical equipment according to claim 8, wherein there is only one way in which the disposable element can be received in the receiving means.
11. Analytical equipment according to claim 8, wherein the analytical equipment includes an air bubble detector.
12. Analytical equipment according to claim 8, wherein the analytical equipment has a supply of enzyme-labelled antibody which antibody immunoreacts with a microorganism to be determined, and a supply of a substrate for the enzyme of the enzyme-labelled antibody which substrate is catalytically converted by the enzyme to a product of electroactivity different to that of the substrate.
13. A method of assaying for biological cells in a liquid sample, which comprises providing analytical equipment for amperometric determination of the biological cells; providing a disposable element comprising a working electrode, a reference electrode, and a filter for retention of biological cells in the vicinity of the electrodes; releasably securing the disposable element to the analytical equipment; bringing the sample in to contact with the filter; bringing a solution of a mediator compound in to contact with the electrodes and the filter; poising the working electrode at an effective potential; and monitoring for current flow at the electrodes.
14. A method of assaying for biological cells in a liquid sample, which comprises providing analytical equipment for amperometric determination of the biological cells; providing a disposable element comprising a working electrode, a reference electrode, and a filter for retention of biological cells in the vicinity of the electrodes; releasably securing the disposable element to the analytical equipment; bringing the sample in to contact with the filter; bringing a solution of an enzyme-labelled antibody in to contact with the electrodes and the filter, the antibody immunoreacting with a microorganism to be determined; and bringing a solution of a substrate in to contact with the electrodes and the filter, the substrate being substrate for the enzyme of the enzyme-labelled antibody; allowing the enzyme to catalyse conversion of the substrate to a product of electroactivity different to that of the substrate; poising the working electrode at an effective potential; and monitoring for current flow at the electrodes.
15. A method of assaying for biological cells in a liquid sample, which comprises providing analytical equipment for amperometric determination of the biological cells; providing a disposable element comprising a working electrode, a reference electrode, and a filter for retention of biological cells in the vicinity of the electrodes; releasably securing the disposable element to the analytical equipment; bringing the sample in to contact with the filter; bringing a solution of an enzyme substrate in to contact with the electrodes and the filter, the substrate being substrate for an enzyme of the biological cells allowing the enzyme to catalyse conversion of the substrate to a product of electroactivity different to that of the substrate; poising the working electrode at an effective potential; and monitoring for current flow at the electrodes.
16. A disposable element for use in analytical equipment for a bioelectrochemical determination, the disposable element comprising a base plate having an aperture for flow of liquid through said element, a working electrode coated on a face of said base plate, a reference electrode coated on said face of said base plate, a fusible electrically conducting link which may be fused to ensure single use of the disposable element, and a filter in contact with said base plate for retention of solids in the vicinity of said electrodes for determination.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8817421.4 | 1988-07-21 | ||
| GB888817421A GB8817421D0 (en) | 1988-07-21 | 1988-07-21 | Bioelectrochemical electrodes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1313397C true CA1313397C (en) | 1993-02-02 |
Family
ID=10640893
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000606230A Expired - Fee Related CA1313397C (en) | 1988-07-21 | 1989-07-20 | Disposable bioelectrochemical electrodes |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US5126034A (en) |
| EP (2) | EP0593096A3 (en) |
| JP (1) | JPH02112752A (en) |
| AU (1) | AU622196B2 (en) |
| CA (1) | CA1313397C (en) |
| GB (1) | GB8817421D0 (en) |
Families Citing this family (271)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2050057A1 (en) | 1991-03-04 | 1992-09-05 | Adam Heller | Interferant eliminating biosensors |
| US5593852A (en) | 1993-12-02 | 1997-01-14 | Heller; Adam | Subcutaneous glucose electrode |
| US5230783A (en) * | 1991-05-15 | 1993-07-27 | The Dow Chemical Company | Electrolytic cell and process for the labeling of proteins and peptides |
| DE69219686T2 (en) * | 1991-07-29 | 1997-09-11 | Mochida Pharm Co Ltd | Method and device for use in specific binding tests |
| IT1253176B (en) * | 1991-11-20 | 1995-07-10 | METHOD FOR THE QUICK DETERMINATION OF THE CONTENT OF MICROORGANISMS IN LIQUIDS AND FLUID SOLUTIONS, AND EQUIPMENT FOR THE IMPLEMENTATION OF SUCH METHOD. | |
| JP3084877B2 (en) * | 1992-01-21 | 2000-09-04 | 松下電器産業株式会社 | Manufacturing method of glucose sensor |
| US5391272A (en) * | 1992-03-06 | 1995-02-21 | Andcare, Inc. | Electrochemical immunoassay methods |
| US5710011A (en) * | 1992-06-05 | 1998-01-20 | Medisense, Inc. | Mediators to oxidoreductase enzymes |
| FR2695481B1 (en) * | 1992-09-07 | 1994-12-02 | Cylergie Gie | Amperometric measurement device comprising an electrochemical sensor. |
| US5330625A (en) * | 1992-10-23 | 1994-07-19 | Eastman Kodak Company | Round potentiometric slide elements and method of using the same |
| US5385846A (en) * | 1993-06-03 | 1995-01-31 | Boehringer Mannheim Corporation | Biosensor and method for hematocrit determination |
| DE4401400A1 (en) * | 1994-01-19 | 1995-07-20 | Ernst Prof Dr Pfeiffer | Method and arrangement for continuously monitoring the concentration of a metabolite |
| AUPM506894A0 (en) * | 1994-04-14 | 1994-05-05 | Memtec Limited | Novel electrochemical cells |
| GB9416002D0 (en) * | 1994-08-08 | 1994-09-28 | Univ Cranfield | Fluid transport device |
| AT402452B (en) * | 1994-09-14 | 1997-05-26 | Avl Verbrennungskraft Messtech | PLANAR SENSOR FOR DETECTING A CHEMICAL PARAMETER OF A SAMPLE |
| JPH08226910A (en) * | 1995-02-22 | 1996-09-03 | Masao Karube | Microbial electrode and microbial sensor |
| FR2733055B1 (en) * | 1995-04-12 | 1997-12-19 | Chemodyne Sa | NEW DEVICE FOR STUDYING ORGANOTYPICAL CULTURES AND ITS APPLICATIONS IN ELECTROPHYSIOLOGY |
| AUPN239395A0 (en) * | 1995-04-12 | 1995-05-11 | Memtec Limited | Method of defining an electrode area |
| US5534132A (en) * | 1995-05-04 | 1996-07-09 | Vreeke; Mark | Electrode and method for the detection of an affinity reaction |
| KR0156176B1 (en) * | 1995-06-01 | 1998-12-01 | 구자홍 | Electrochemical immune biosensor |
| AUPN363995A0 (en) | 1995-06-19 | 1995-07-13 | Memtec Limited | Electrochemical cell |
| US6413410B1 (en) | 1996-06-19 | 2002-07-02 | Lifescan, Inc. | Electrochemical cell |
| US5639672A (en) * | 1995-10-16 | 1997-06-17 | Lxn Corporation | Electrochemical determination of fructosamine |
| US6638415B1 (en) * | 1995-11-16 | 2003-10-28 | Lifescan, Inc. | Antioxidant sensor |
| US6521110B1 (en) | 1995-11-16 | 2003-02-18 | Lifescan, Inc. | Electrochemical cell |
| AUPN661995A0 (en) * | 1995-11-16 | 1995-12-07 | Memtec America Corporation | Electrochemical cell 2 |
| US6863801B2 (en) | 1995-11-16 | 2005-03-08 | Lifescan, Inc. | Electrochemical cell |
| US5989917A (en) * | 1996-02-13 | 1999-11-23 | Selfcare, Inc. | Glucose monitor and test strip containers for use in same |
| US5708247A (en) * | 1996-02-14 | 1998-01-13 | Selfcare, Inc. | Disposable glucose test strips, and methods and compositions for making same |
| US7112265B1 (en) * | 1996-02-14 | 2006-09-26 | Lifescan Scotland Limited | Disposable test strips with integrated reagent/blood separation layer |
| US6241862B1 (en) | 1996-02-14 | 2001-06-05 | Inverness Medical Technology, Inc. | Disposable test strips with integrated reagent/blood separation layer |
| GB2322707B (en) * | 1996-06-17 | 2000-07-12 | Mercury Diagnostics Inc | Electrochemical test device and related methods |
| US6632349B1 (en) * | 1996-11-15 | 2003-10-14 | Lifescan, Inc. | Hemoglobin sensor |
| JP3460183B2 (en) * | 1996-12-24 | 2003-10-27 | 松下電器産業株式会社 | Biosensor |
| JP3487396B2 (en) * | 1997-01-31 | 2004-01-19 | 松下電器産業株式会社 | Biosensor and manufacturing method thereof |
| JP3394262B2 (en) | 1997-02-06 | 2003-04-07 | セラセンス、インク． | Small volume in vitro analyte sensor |
| EP0859229A1 (en) * | 1997-02-10 | 1998-08-19 | Gist-Brocades B.V. | Detection of analytes using electrochemistry |
| AU5301598A (en) * | 1997-02-10 | 1998-08-13 | Gist-Brocades B.V. | Detection of analytes using electrochemistry |
| EP0859230A1 (en) * | 1997-02-10 | 1998-08-19 | Cranfield University | Detection of analytes using electrochemistry |
| US6068747A (en) * | 1997-03-10 | 2000-05-30 | Denso Corporation | Solid electrolyte gas sensor |
| AUPO581397A0 (en) | 1997-03-21 | 1997-04-17 | Memtec America Corporation | Sensor connection means |
| AUPO585797A0 (en) * | 1997-03-25 | 1997-04-24 | Memtec America Corporation | Improved electrochemical cell |
| KR100241928B1 (en) * | 1997-03-31 | 2000-03-02 | 박종근 | Determination device in which the electrode is integrally formed on the porous thin film and the quantification method using the same |
| GB9711395D0 (en) | 1997-06-04 | 1997-07-30 | Environmental Sensors Ltd | Improvements to electrodes for the measurement of analytes in small samples |
| GB9824627D0 (en) * | 1998-11-11 | 1999-01-06 | Cambridge Sensors Ltd | Test strips for small volumes |
| AUPO855897A0 (en) * | 1997-08-13 | 1997-09-04 | Usf Filtration And Separations Group Inc. | Automatic analysing apparatus II |
| US6129823A (en) * | 1997-09-05 | 2000-10-10 | Abbott Laboratories | Low volume electrochemical sensor |
| US6736957B1 (en) * | 1997-10-16 | 2004-05-18 | Abbott Laboratories | Biosensor electrode mediators for regeneration of cofactors and process for using |
| CO5040209A1 (en) | 1997-10-16 | 2001-05-29 | Abbott Lab | BIOSENSOR ELECTRODES MEDIATORS OF COFACTOR REGENERATION |
| US6036924A (en) | 1997-12-04 | 2000-03-14 | Hewlett-Packard Company | Cassette of lancet cartridges for sampling blood |
| US5997817A (en) | 1997-12-05 | 1999-12-07 | Roche Diagnostics Corporation | Electrochemical biosensor test strip |
| US6134461A (en) | 1998-03-04 | 2000-10-17 | E. Heller & Company | Electrochemical analyte |
| US6103033A (en) | 1998-03-04 | 2000-08-15 | Therasense, Inc. | Process for producing an electrochemical biosensor |
| US6878251B2 (en) * | 1998-03-12 | 2005-04-12 | Lifescan, Inc. | Heated electrochemical cell |
| US6475360B1 (en) | 1998-03-12 | 2002-11-05 | Lifescan, Inc. | Heated electrochemical cell |
| US6652734B1 (en) | 1999-03-16 | 2003-11-25 | Lifescan, Inc. | Sensor with improved shelf life |
| US6391005B1 (en) | 1998-03-30 | 2002-05-21 | Agilent Technologies, Inc. | Apparatus and method for penetration with shaft having a sensor for sensing penetration depth |
| US6175752B1 (en) | 1998-04-30 | 2001-01-16 | Therasense, Inc. | Analyte monitoring device and methods of use |
| US9066695B2 (en) | 1998-04-30 | 2015-06-30 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US8346337B2 (en) | 1998-04-30 | 2013-01-01 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US8480580B2 (en) | 1998-04-30 | 2013-07-09 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US8465425B2 (en) | 1998-04-30 | 2013-06-18 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US8974386B2 (en) | 1998-04-30 | 2015-03-10 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US8688188B2 (en) | 1998-04-30 | 2014-04-01 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US6949816B2 (en) | 2003-04-21 | 2005-09-27 | Motorola, Inc. | Semiconductor component having first surface area for electrically coupling to a semiconductor chip and second surface area for electrically coupling to a substrate, and method of manufacturing same |
| GB2337122B (en) * | 1998-05-08 | 2002-11-13 | Medisense Inc | Test strip |
| US6761816B1 (en) * | 1998-06-23 | 2004-07-13 | Clinical Micro Systems, Inc. | Printed circuit boards with monolayers and capture ligands |
| US7087148B1 (en) | 1998-06-23 | 2006-08-08 | Clinical Micro Sensors, Inc. | Binding acceleration techniques for the detection of analytes |
| US20050244954A1 (en) * | 1998-06-23 | 2005-11-03 | Blackburn Gary F | Binding acceleration techniques for the detection of analytes |
| US6495023B1 (en) * | 1998-07-09 | 2002-12-17 | Michigan State University | Electrochemical methods for generation of a biological proton motive force and pyridine nucleotide cofactor regeneration |
| US6805788B1 (en) * | 1998-07-10 | 2004-10-19 | Lynntech, Inc. | Electrochemical impedance evaluation and inspection sensor |
| US6500571B2 (en) | 1998-08-19 | 2002-12-31 | Powerzyme, Inc. | Enzymatic fuel cell |
| US6251260B1 (en) | 1998-08-24 | 2001-06-26 | Therasense, Inc. | Potentiometric sensors for analytic determination |
| US6338790B1 (en) | 1998-10-08 | 2002-01-15 | Therasense, Inc. | Small volume in vitro analyte sensor with diffusible or non-leachable redox mediator |
| US6591125B1 (en) | 2000-06-27 | 2003-07-08 | Therasense, Inc. | Small volume in vitro analyte sensor with diffusible or non-leachable redox mediator |
| US6203767B1 (en) | 1998-11-06 | 2001-03-20 | Steris Corporation | Peracetic acid card reader and card style sensor |
| DE60031248T2 (en) * | 1999-02-18 | 2007-05-24 | Biovalve Technologies, Inc., North Grafton | ELECTROACTIVE PORE |
| US6391577B1 (en) * | 1999-03-03 | 2002-05-21 | Susan R. Mikkelsen | Rapid electrochemical assay for antibiotic and cytotoxic drug susceptibility in microorganisms |
| FR2792338B1 (en) | 1999-04-15 | 2001-08-10 | France Etat | METHOD AND DEVICE FOR DETERMINING THE EXISTENCE OF A BIOLOGICAL ACTIVITY OF MICROORGANISMS |
| US7312087B2 (en) * | 2000-01-11 | 2007-12-25 | Clinical Micro Sensors, Inc. | Devices and methods for biochip multiplexing |
| US20020177135A1 (en) * | 1999-07-27 | 2002-11-28 | Doung Hau H. | Devices and methods for biochip multiplexing |
| US6654625B1 (en) | 1999-06-18 | 2003-11-25 | Therasense, Inc. | Mass transport limited in vivo analyte sensor |
| JP2001004581A (en) * | 1999-06-24 | 2001-01-12 | Sentan Kagaku Gijutsu Incubation Center:Kk | Very small reference electrode |
| US6662439B1 (en) * | 1999-10-04 | 2003-12-16 | Roche Diagnostics Corporation | Laser defined features for patterned laminates and electrodes |
| US6645359B1 (en) * | 2000-10-06 | 2003-11-11 | Roche Diagnostics Corporation | Biosensor |
| US6616819B1 (en) | 1999-11-04 | 2003-09-09 | Therasense, Inc. | Small volume in vitro analyte sensor and methods |
| EP1152239A4 (en) | 1999-11-15 | 2009-05-27 | Panasonic Corp | Biosensor, method of forming thin-film electrode, and method and apparatus for quantitative determination |
| US6824669B1 (en) * | 2000-02-17 | 2004-11-30 | Motorola, Inc. | Protein and peptide sensors using electrical detection methods |
| US6612111B1 (en) | 2000-03-27 | 2003-09-02 | Lifescan, Inc. | Method and device for sampling and analyzing interstitial fluid and whole blood samples |
| US6571651B1 (en) * | 2000-03-27 | 2003-06-03 | Lifescan, Inc. | Method of preventing short sampling of a capillary or wicking fill device |
| EP1272671A2 (en) * | 2000-03-30 | 2003-01-08 | Infineon Technologies AG | Biosensor, biosensor array, method for producing an electrode of a biosensor, method for producing a biosensor |
| DE10015816A1 (en) * | 2000-03-30 | 2001-10-18 | Infineon Technologies Ag | Biosensor chip |
| CA2343873A1 (en) * | 2000-04-12 | 2001-10-12 | Wako Pure Chemical Industries Ltd. | Electrode for dielectrophoretic apparatus, dielectrophoretic apparatus, methdo for manufacturing the same, and method for separating substances using the elctrode or dielectrophoretic apparatus |
| US6541243B1 (en) | 2000-06-05 | 2003-04-01 | Axon Instruments, Inc. | Perfusion chamber for electrophysiological testing of oocytes |
| US6444115B1 (en) | 2000-07-14 | 2002-09-03 | Lifescan, Inc. | Electrochemical method for measuring chemical reaction rates |
| RU2278612C2 (en) * | 2000-07-14 | 2006-06-27 | Лайфскен, Инк. | Immune sensor |
| US8641644B2 (en) | 2000-11-21 | 2014-02-04 | Sanofi-Aventis Deutschland Gmbh | Blood testing apparatus having a rotatable cartridge with multiple lancing elements and testing means |
| US6560471B1 (en) | 2001-01-02 | 2003-05-06 | Therasense, Inc. | Analyte monitoring device and methods of use |
| EP1397068A2 (en) | 2001-04-02 | 2004-03-17 | Therasense, Inc. | Blood glucose tracking apparatus and methods |
| WO2002086999A1 (en) * | 2001-04-13 | 2002-10-31 | Powerzyme, Inc | Enzymatic fuel cell |
| US20030031911A1 (en) * | 2001-04-13 | 2003-02-13 | Rosalyn Ritts | Biocompatible membranes and fuel cells produced therewith |
| US20030113606A1 (en) * | 2001-04-13 | 2003-06-19 | Rosalyn Ritts | Biocompatible membranes of block copolymers and fuel cells produced therewith |
| US20030049511A1 (en) * | 2001-04-13 | 2003-03-13 | Rosalyn Ritts | Stabilized biocompatible membranes of block copolymers and fuel cells produced therewith |
| US20050009101A1 (en) * | 2001-05-17 | 2005-01-13 | Motorola, Inc. | Microfluidic devices comprising biochannels |
| US7250288B2 (en) * | 2001-05-31 | 2007-07-31 | Board Of Trustees Of Michigan State University | Electrode compositions and configurations for electrochemical bioreactor systems |
| US9427532B2 (en) | 2001-06-12 | 2016-08-30 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
| US9226699B2 (en) | 2002-04-19 | 2016-01-05 | Sanofi-Aventis Deutschland Gmbh | Body fluid sampling module with a continuous compression tissue interface surface |
| ES2352998T3 (en) | 2001-06-12 | 2011-02-24 | Pelikan Technologies Inc. | LANCETA ELECTRIC ACTUATOR. |
| US8337419B2 (en) | 2002-04-19 | 2012-12-25 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
| AU2002344825A1 (en) | 2001-06-12 | 2002-12-23 | Pelikan Technologies, Inc. | Method and apparatus for improving success rate of blood yield from a fingerstick |
| CA2448905C (en) | 2001-06-12 | 2010-09-07 | Pelikan Technologies, Inc. | Blood sampling apparatus and method |
| US7981056B2 (en) | 2002-04-19 | 2011-07-19 | Pelikan Technologies, Inc. | Methods and apparatus for lancet actuation |
| US9795747B2 (en) | 2010-06-02 | 2017-10-24 | Sanofi-Aventis Deutschland Gmbh | Methods and apparatus for lancet actuation |
| US7025774B2 (en) | 2001-06-12 | 2006-04-11 | Pelikan Technologies, Inc. | Tissue penetration device |
| CA2448902C (en) | 2001-06-12 | 2010-09-07 | Pelikan Technologies, Inc. | Self optimizing lancing device with adaptation means to temporal variations in cutaneous properties |
| WO2002100254A2 (en) | 2001-06-12 | 2002-12-19 | Pelikan Technologies, Inc. | Method and apparatus for lancet launching device integrated onto a blood-sampling cartridge |
| WO2003029804A1 (en) * | 2001-09-28 | 2003-04-10 | Arkray, Inc. | Measurement instrument and concentration measurement apparatus |
| AU2002340079A1 (en) | 2001-10-10 | 2003-04-22 | Lifescan Inc. | Electrochemical cell |
| US20030175947A1 (en) * | 2001-11-05 | 2003-09-18 | Liu Robin Hui | Enhanced mixing in microfluidic devices |
| WO2003050897A2 (en) * | 2001-12-11 | 2003-06-19 | Powerzyme, Inc. | Biocompatible membranes of block copolymers and fuel cells produced therewith |
| US20060134713A1 (en) * | 2002-03-21 | 2006-06-22 | Lifescan, Inc. | Biosensor apparatus and methods of use |
| US20030180814A1 (en) * | 2002-03-21 | 2003-09-25 | Alastair Hodges | Direct immunosensor assay |
| GB0207845D0 (en) * | 2002-04-04 | 2002-05-15 | Lgc Ltd | Apparatus, methods and means for biochemical analysis |
| US9314194B2 (en) | 2002-04-19 | 2016-04-19 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
| US9248267B2 (en) | 2002-04-19 | 2016-02-02 | Sanofi-Aventis Deustchland Gmbh | Tissue penetration device |
| US7674232B2 (en) | 2002-04-19 | 2010-03-09 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7901362B2 (en) | 2002-04-19 | 2011-03-08 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7547287B2 (en) | 2002-04-19 | 2009-06-16 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US9795334B2 (en) | 2002-04-19 | 2017-10-24 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
| US7909778B2 (en) | 2002-04-19 | 2011-03-22 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7175642B2 (en) | 2002-04-19 | 2007-02-13 | Pelikan Technologies, Inc. | Methods and apparatus for lancet actuation |
| US7232451B2 (en) | 2002-04-19 | 2007-06-19 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7297122B2 (en) | 2002-04-19 | 2007-11-20 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US8579831B2 (en) | 2002-04-19 | 2013-11-12 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
| US7648468B2 (en) | 2002-04-19 | 2010-01-19 | Pelikon Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7976476B2 (en) | 2002-04-19 | 2011-07-12 | Pelikan Technologies, Inc. | Device and method for variable speed lancet |
| US8360992B2 (en) | 2002-04-19 | 2013-01-29 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
| US7582099B2 (en) | 2002-04-19 | 2009-09-01 | Pelikan Technologies, Inc | Method and apparatus for penetrating tissue |
| US7331931B2 (en) | 2002-04-19 | 2008-02-19 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US8372016B2 (en) | 2002-04-19 | 2013-02-12 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for body fluid sampling and analyte sensing |
| US7229458B2 (en) | 2002-04-19 | 2007-06-12 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7713214B2 (en) | 2002-04-19 | 2010-05-11 | Pelikan Technologies, Inc. | Method and apparatus for a multi-use body fluid sampling device with optical analyte sensing |
| US8702624B2 (en) | 2006-09-29 | 2014-04-22 | Sanofi-Aventis Deutschland Gmbh | Analyte measurement device with a single shot actuator |
| US8221334B2 (en) | 2002-04-19 | 2012-07-17 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
| US7291117B2 (en) | 2002-04-19 | 2007-11-06 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7717863B2 (en) | 2002-04-19 | 2010-05-18 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7892183B2 (en) | 2002-04-19 | 2011-02-22 | Pelikan Technologies, Inc. | Method and apparatus for body fluid sampling and analyte sensing |
| US8784335B2 (en) | 2002-04-19 | 2014-07-22 | Sanofi-Aventis Deutschland Gmbh | Body fluid sampling device with a capacitive sensor |
| US8267870B2 (en) | 2002-04-19 | 2012-09-18 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for body fluid sampling with hybrid actuation |
| US7491178B2 (en) | 2002-04-19 | 2009-02-17 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
| US7371247B2 (en) | 2002-04-19 | 2008-05-13 | Pelikan Technologies, Inc | Method and apparatus for penetrating tissue |
| KR100446406B1 (en) * | 2002-05-14 | 2004-09-01 | 한국과학기술연구원 | A Membraneless And Mediatorless Microbial Fuel Cell |
| US7238496B2 (en) * | 2002-08-06 | 2007-07-03 | The Board Of Trustees Of The University Of Arkansas | Rapid and automated electrochemical method for detection of viable microbial pathogens |
| US20040108226A1 (en) * | 2002-10-28 | 2004-06-10 | Constantin Polychronakos | Continuous glucose quantification device and method |
| US7381184B2 (en) | 2002-11-05 | 2008-06-03 | Abbott Diabetes Care Inc. | Sensor inserter assembly |
| US8574895B2 (en) | 2002-12-30 | 2013-11-05 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus using optical techniques to measure analyte levels |
| AU2003303597A1 (en) | 2002-12-31 | 2004-07-29 | Therasense, Inc. | Continuous glucose monitoring system and methods of use |
| US8771183B2 (en) | 2004-02-17 | 2014-07-08 | Abbott Diabetes Care Inc. | Method and system for providing data communication in continuous glucose monitoring and management system |
| CN100504372C (en) * | 2003-02-14 | 2009-06-24 | 爱科来株式会社 | Analyzing tool with knob part |
| US7473264B2 (en) | 2003-03-28 | 2009-01-06 | Lifescan, Inc. | Integrated lance and strip for analyte measurement |
| US20040193202A1 (en) | 2003-03-28 | 2004-09-30 | Allen John J. | Integrated lance and strip for analyte measurement |
| EP2238892A3 (en) | 2003-05-30 | 2011-02-09 | Pelikan Technologies Inc. | Apparatus for body fluid sampling |
| US7850621B2 (en) | 2003-06-06 | 2010-12-14 | Pelikan Technologies, Inc. | Method and apparatus for body fluid sampling and analyte sensing |
| US8066639B2 (en) | 2003-06-10 | 2011-11-29 | Abbott Diabetes Care Inc. | Glucose measuring device for use in personal area network |
| WO2006001797A1 (en) | 2004-06-14 | 2006-01-05 | Pelikan Technologies, Inc. | Low pain penetrating |
| US7920906B2 (en) | 2005-03-10 | 2011-04-05 | Dexcom, Inc. | System and methods for processing analyte sensor data for sensor calibration |
| WO2005033659A2 (en) | 2003-09-29 | 2005-04-14 | Pelikan Technologies, Inc. | Method and apparatus for an improved sample capture device |
| WO2005037095A1 (en) | 2003-10-14 | 2005-04-28 | Pelikan Technologies, Inc. | Method and apparatus for a variable user interface |
| USD914881S1 (en) | 2003-11-05 | 2021-03-30 | Abbott Diabetes Care Inc. | Analyte sensor electronic mount |
| US9247900B2 (en) | 2004-07-13 | 2016-02-02 | Dexcom, Inc. | Analyte sensor |
| US20070099259A1 (en) * | 2003-12-15 | 2007-05-03 | Rapid Laboratory Microsystems Inc. | Electrochemical assay for the identification of microorganisms |
| US8668656B2 (en) | 2003-12-31 | 2014-03-11 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for improving fluidic flow and sample capture |
| US7822454B1 (en) | 2005-01-03 | 2010-10-26 | Pelikan Technologies, Inc. | Fluid sampling device with improved analyte detecting member configuration |
| EP1751546A2 (en) | 2004-05-20 | 2007-02-14 | Albatros Technologies GmbH & Co. KG | Printable hydrogel for biosensors |
| US9775553B2 (en) | 2004-06-03 | 2017-10-03 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for a fluid sampling device |
| WO2005120365A1 (en) | 2004-06-03 | 2005-12-22 | Pelikan Technologies, Inc. | Method and apparatus for a fluid sampling device |
| US20050284757A1 (en) * | 2004-06-29 | 2005-12-29 | Allen John J | Analyte measuring system which prevents the reuse of a test strip |
| US20050284773A1 (en) * | 2004-06-29 | 2005-12-29 | Allen John J | Method of preventing reuse in an analyte measuring system |
| US20070045902A1 (en) | 2004-07-13 | 2007-03-01 | Brauker James H | Analyte sensor |
| US8170803B2 (en) | 2004-07-13 | 2012-05-01 | Dexcom, Inc. | Transcutaneous analyte sensor |
| US9572534B2 (en) | 2010-06-29 | 2017-02-21 | Abbott Diabetes Care Inc. | Devices, systems and methods for on-skin or on-body mounting of medical devices |
| US8029441B2 (en) | 2006-02-28 | 2011-10-04 | Abbott Diabetes Care Inc. | Analyte sensor transmitter unit configuration for a data monitoring and management system |
| US8571624B2 (en) | 2004-12-29 | 2013-10-29 | Abbott Diabetes Care Inc. | Method and apparatus for mounting a data transmission device in a communication system |
| US9788771B2 (en) | 2006-10-23 | 2017-10-17 | Abbott Diabetes Care Inc. | Variable speed sensor insertion devices and methods of use |
| US9259175B2 (en) | 2006-10-23 | 2016-02-16 | Abbott Diabetes Care, Inc. | Flexible patch for fluid delivery and monitoring body analytes |
| US7697967B2 (en) | 2005-12-28 | 2010-04-13 | Abbott Diabetes Care Inc. | Method and apparatus for providing analyte sensor insertion |
| US8333714B2 (en) | 2006-09-10 | 2012-12-18 | Abbott Diabetes Care Inc. | Method and system for providing an integrated analyte sensor insertion device and data processing unit |
| US9743862B2 (en) | 2011-03-31 | 2017-08-29 | Abbott Diabetes Care Inc. | Systems and methods for transcutaneously implanting medical devices |
| US9351669B2 (en) | 2009-09-30 | 2016-05-31 | Abbott Diabetes Care Inc. | Interconnect for on-body analyte monitoring device |
| US20090105569A1 (en) | 2006-04-28 | 2009-04-23 | Abbott Diabetes Care, Inc. | Introducer Assembly and Methods of Use |
| US10226207B2 (en) | 2004-12-29 | 2019-03-12 | Abbott Diabetes Care Inc. | Sensor inserter having introducer |
| US8545403B2 (en) | 2005-12-28 | 2013-10-01 | Abbott Diabetes Care Inc. | Medical device insertion |
| US8512243B2 (en) | 2005-09-30 | 2013-08-20 | Abbott Diabetes Care Inc. | Integrated introducer and transmitter assembly and methods of use |
| US7883464B2 (en) | 2005-09-30 | 2011-02-08 | Abbott Diabetes Care Inc. | Integrated transmitter unit and sensor introducer mechanism and methods of use |
| US7731657B2 (en) | 2005-08-30 | 2010-06-08 | Abbott Diabetes Care Inc. | Analyte sensor introducer and methods of use |
| US9398882B2 (en) | 2005-09-30 | 2016-07-26 | Abbott Diabetes Care Inc. | Method and apparatus for providing analyte sensor and data processing device |
| US8652831B2 (en) | 2004-12-30 | 2014-02-18 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for analyte measurement test time |
| US8112240B2 (en) | 2005-04-29 | 2012-02-07 | Abbott Diabetes Care Inc. | Method and apparatus for providing leak detection in data monitoring and management systems |
| GB0517773D0 (en) * | 2005-09-01 | 2005-10-12 | Palintest Ltd | Electrochemical sensor |
| US20070068806A1 (en) * | 2005-09-27 | 2007-03-29 | Health & Life Co., Ltd | Biosensor strip having an identification function and its sensor |
| US9521968B2 (en) | 2005-09-30 | 2016-12-20 | Abbott Diabetes Care Inc. | Analyte sensor retention mechanism and methods of use |
| US8153444B2 (en) * | 2005-10-13 | 2012-04-10 | Auric Enterprises, Llc | Immuno gold lateral flow assay |
| US7344893B2 (en) * | 2005-10-13 | 2008-03-18 | Auric Enterprises, Llc | Immuno-gold lateral flow assay |
| US7766829B2 (en) | 2005-11-04 | 2010-08-03 | Abbott Diabetes Care Inc. | Method and system for providing basal profile modification in analyte monitoring and management systems |
| TWI285739B (en) * | 2005-12-20 | 2007-08-21 | Univ Feng Chia | Electrochemical testing device |
| US11298058B2 (en) | 2005-12-28 | 2022-04-12 | Abbott Diabetes Care Inc. | Method and apparatus for providing analyte sensor insertion |
| GB0601703D0 (en) | 2006-01-27 | 2006-03-08 | Intellitect Water Ltd | Improvement To The Design And Construction Of Electrochemical Sensors |
| US7885698B2 (en) | 2006-02-28 | 2011-02-08 | Abbott Diabetes Care Inc. | Method and system for providing continuous calibration of implantable analyte sensors |
| US7620438B2 (en) | 2006-03-31 | 2009-11-17 | Abbott Diabetes Care Inc. | Method and system for powering an electronic device |
| US8226891B2 (en) | 2006-03-31 | 2012-07-24 | Abbott Diabetes Care Inc. | Analyte monitoring devices and methods therefor |
| US8529751B2 (en) * | 2006-03-31 | 2013-09-10 | Lifescan, Inc. | Systems and methods for discriminating control solution from a physiological sample |
| US7920907B2 (en) | 2006-06-07 | 2011-04-05 | Abbott Diabetes Care Inc. | Analyte monitoring system and method |
| US20080160543A1 (en) * | 2006-12-27 | 2008-07-03 | Chein-Shyong Su | Electrochemical immunostrip and its preparation method |
| US8930203B2 (en) | 2007-02-18 | 2015-01-06 | Abbott Diabetes Care Inc. | Multi-function analyte test device and methods therefor |
| US8732188B2 (en) | 2007-02-18 | 2014-05-20 | Abbott Diabetes Care Inc. | Method and system for providing contextual based medication dosage determination |
| US8123686B2 (en) | 2007-03-01 | 2012-02-28 | Abbott Diabetes Care Inc. | Method and apparatus for providing rolling data in communication systems |
| US8461985B2 (en) | 2007-05-08 | 2013-06-11 | Abbott Diabetes Care Inc. | Analyte monitoring system and methods |
| US8456301B2 (en) | 2007-05-08 | 2013-06-04 | Abbott Diabetes Care Inc. | Analyte monitoring system and methods |
| US8665091B2 (en) | 2007-05-08 | 2014-03-04 | Abbott Diabetes Care Inc. | Method and device for determining elapsed sensor life |
| US7928850B2 (en) | 2007-05-08 | 2011-04-19 | Abbott Diabetes Care Inc. | Analyte monitoring system and methods |
| WO2008150917A1 (en) | 2007-05-31 | 2008-12-11 | Abbott Diabetes Care, Inc. | Insertion devices and methods |
| TW200914826A (en) * | 2007-09-21 | 2009-04-01 | Apex Biotechnology Corp | Electrochemical quantitative analysis system and method for the same |
| US8778168B2 (en) * | 2007-09-28 | 2014-07-15 | Lifescan, Inc. | Systems and methods of discriminating control solution from a physiological sample |
| US8513371B2 (en) * | 2007-12-31 | 2013-08-20 | Bridgestone Corporation | Amino alkoxy-modified silsesquioxanes and method of preparation |
| US8603768B2 (en) | 2008-01-17 | 2013-12-10 | Lifescan, Inc. | System and method for measuring an analyte in a sample |
| US9386944B2 (en) | 2008-04-11 | 2016-07-12 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for analyte detecting device |
| WO2009149309A1 (en) * | 2008-06-04 | 2009-12-10 | Crookes, Donald, W. | Microbial fuel cell and method of use |
| US8551320B2 (en) | 2008-06-09 | 2013-10-08 | Lifescan, Inc. | System and method for measuring an analyte in a sample |
| JP5405916B2 (en) * | 2008-06-24 | 2014-02-05 | パナソニック株式会社 | Biosensor, method for manufacturing the same, and detection system including the same |
| US8103456B2 (en) | 2009-01-29 | 2012-01-24 | Abbott Diabetes Care Inc. | Method and device for early signal attenuation detection using blood glucose measurements |
| US9375169B2 (en) | 2009-01-30 | 2016-06-28 | Sanofi-Aventis Deutschland Gmbh | Cam drive for managing disposable penetrating member actions with a single motor and motor and control system |
| US9402544B2 (en) | 2009-02-03 | 2016-08-02 | Abbott Diabetes Care Inc. | Analyte sensor and apparatus for insertion of the sensor |
| US20100213057A1 (en) | 2009-02-26 | 2010-08-26 | Benjamin Feldman | Self-Powered Analyte Sensor |
| WO2010127050A1 (en) | 2009-04-28 | 2010-11-04 | Abbott Diabetes Care Inc. | Error detection in critical repeating data in a wireless sensor system |
| US9184490B2 (en) | 2009-05-29 | 2015-11-10 | Abbott Diabetes Care Inc. | Medical device antenna systems having external antenna configurations |
| EP2473963A4 (en) | 2009-08-31 | 2014-01-08 | Abbott Diabetes Care Inc | Medical devices and methods |
| WO2011026147A1 (en) | 2009-08-31 | 2011-03-03 | Abbott Diabetes Care Inc. | Analyte signal processing device and methods |
| EP2473099A4 (en) | 2009-08-31 | 2015-01-14 | Abbott Diabetes Care Inc | Analyte monitoring system and methods for managing power and noise |
| US9320461B2 (en) | 2009-09-29 | 2016-04-26 | Abbott Diabetes Care Inc. | Method and apparatus for providing notification function in analyte monitoring systems |
| JP5659360B2 (en) * | 2009-12-15 | 2015-01-28 | パナソニックヘルスケアホールディングス株式会社 | Microbe count measuring device |
| US8308935B2 (en) * | 2010-01-25 | 2012-11-13 | R3Dstar Biomedical Corp. | Bio-sensing device capable of automatically detecting sensing code and sensing method thereof |
| USD924406S1 (en) | 2010-02-01 | 2021-07-06 | Abbott Diabetes Care Inc. | Analyte sensor inserter |
| EP2549918B2 (en) | 2010-03-24 | 2023-01-25 | Abbott Diabetes Care, Inc. | Medical device inserters and processes of inserting and using medical devices |
| CN102207483B (en) * | 2010-03-29 | 2013-11-06 | 晶镭科技股份有限公司 | Biological sensing device capable of detecting strip code and insufficient filling of sample |
| US8965476B2 (en) | 2010-04-16 | 2015-02-24 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
| US11064921B2 (en) | 2010-06-29 | 2021-07-20 | Abbott Diabetes Care Inc. | Devices, systems and methods for on-skin or on-body mounting of medical devices |
| US20120048746A1 (en) * | 2010-08-30 | 2012-03-01 | Cilag Gmbh International | Analyte test strip with electrically distinguishable divided electrode |
| CN101943677B (en) * | 2010-09-07 | 2013-01-09 | 东南大学 | Blue green algae concentration monitoring system with microorganism fuel cell power supply |
| AU2012335830B2 (en) | 2011-11-07 | 2017-05-04 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods |
| EP4056105B1 (en) | 2011-12-11 | 2023-10-11 | Abbott Diabetes Care, Inc. | Analyte sensor devices |
| US9968306B2 (en) | 2012-09-17 | 2018-05-15 | Abbott Diabetes Care Inc. | Methods and apparatuses for providing adverse condition notification with enhanced wireless communication range in analyte monitoring systems |
| US9389200B2 (en) * | 2012-11-09 | 2016-07-12 | Infineon Technologies Ag | Sensor device, a method and a sensor to determine a relative concentration of a first kind of ions with respect to a second kind of ions solute in a drop of liquid |
| US9523653B2 (en) | 2013-05-09 | 2016-12-20 | Changsha Sinocare Inc. | Disposable test sensor with improved sampling entrance |
| US9518951B2 (en) | 2013-12-06 | 2016-12-13 | Changsha Sinocare Inc. | Disposable test sensor with improved sampling entrance |
| US9897566B2 (en) | 2014-01-13 | 2018-02-20 | Changsha Sinocare Inc. | Disposable test sensor |
| US9939401B2 (en) | 2014-02-20 | 2018-04-10 | Changsha Sinocare Inc. | Test sensor with multiple sampling routes |
| WO2016047114A1 (en) * | 2014-09-25 | 2016-03-31 | パナソニックＩｐマネジメント株式会社 | Electrochemical measuring method and electrochemical measuring device |
| US10213139B2 (en) | 2015-05-14 | 2019-02-26 | Abbott Diabetes Care Inc. | Systems, devices, and methods for assembling an applicator and sensor control device |
| CA2984939A1 (en) | 2015-05-14 | 2016-11-17 | Abbott Diabetes Care Inc. | Compact medical device inserters and related systems and methods |
| KR101763382B1 (en) * | 2015-08-27 | 2017-08-02 | 한국에너지기술연구원 | Working electrode of cell for felt electrode characterization and cell for felt electrode characterization using the same |
| EP3300159A1 (en) * | 2016-09-27 | 2018-03-28 | Centre National De La Recherche Scientifique | Electrochemical cell testing device |
| US11612839B2 (en) * | 2016-10-18 | 2023-03-28 | Massachusetts Institute Of Technology | Systems, devices, and methods for point-of-use testing for fluid contamination |
| WO2018122852A1 (en) | 2016-12-29 | 2018-07-05 | Schnell Amit | Cartridge for use in in-vitro diagnostics and method of use thereof |
| IT201600132760A1 (en) * | 2016-12-30 | 2018-06-30 | Biosensing Tech Srl Via Ausonia 20 00171 Roma It | MULTIPARAMETRIC DEVICE WITH CONTINUOUS FLOW FOR THE MEASUREMENT OF CONDUCTANCE AND AMPEROMETRY APPLIED IN BIOSENSORING |
| CN110461217B (en) | 2017-01-23 | 2022-09-16 | 雅培糖尿病护理公司 | Systems, devices, and methods for analyte sensor insertion |
| JP7283126B2 (en) * | 2019-02-27 | 2023-05-30 | 日本電気硝子株式会社 | electrochemical sensor |
| USD1002852S1 (en) | 2019-06-06 | 2023-10-24 | Abbott Diabetes Care Inc. | Analyte sensor device |
| JP7279791B2 (en) * | 2019-07-05 | 2023-05-23 | 日本電信電話株式会社 | Analyzer and method |
| USD999913S1 (en) | 2020-12-21 | 2023-09-26 | Abbott Diabetes Care Inc | Analyte sensor inserter |
| EP4180805A1 (en) * | 2021-11-12 | 2023-05-17 | Consejo Superior de Investigaciones Cientificas | Screen-printed electrode, manufacturing method thereof, electrochemical sensor comprising said electrode for detecting water pollutants, and operating method of said sensor |
| CN116973424B (en) * | 2023-09-22 | 2023-12-01 | 广东盈峰科技有限公司 | Microorganism electrochemical sensor testing system and method |
Family Cites Families (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2884366A (en) * | 1958-03-21 | 1959-04-28 | Foxboro Co | Bubble trap for liquid systems |
| US3235477A (en) * | 1962-10-12 | 1966-02-15 | Honeywell Inc | Electrical apparatus |
| US3509034A (en) * | 1968-05-29 | 1970-04-28 | T O Paine | Pulse-activated polarographic hydrogen detector |
| US3969209A (en) * | 1975-07-08 | 1976-07-13 | The United States Of America As Represented By The United States Energy Research And Development Administration | Automatic electrochemical ambient air monitor for chloride and chlorine |
| US4534356A (en) * | 1982-07-30 | 1985-08-13 | Diamond Shamrock Chemicals Company | Solid state transcutaneous blood gas sensors |
| CA1226036A (en) * | 1983-05-05 | 1987-08-25 | Irving J. Higgins | Analytical equipment and sensor electrodes therefor |
| US4655880A (en) * | 1983-08-01 | 1987-04-07 | Case Western Reserve University | Apparatus and method for sensing species, substances and substrates using oxidase |
| US4500391A (en) * | 1983-10-13 | 1985-02-19 | Allied Corporation | Method of and system for real time differential pulse detection |
| US4521290A (en) * | 1984-03-16 | 1985-06-04 | Honeywell Inc. | Thin layer electrochemical cell for rapid detection of toxic chemicals |
| US4614716A (en) * | 1984-12-14 | 1986-09-30 | Rohrback Technology Corporation | Filter cell for electrochemically measuring enzyme concentrations |
| EP0230472B2 (en) * | 1985-06-21 | 2000-12-13 | Matsushita Electric Industrial Co., Ltd. | Biosensor and method of manufacturing same |
| GB8523631D0 (en) * | 1985-09-25 | 1985-10-30 | Pena Ltd Paul De | Bioelectrochemical cell |
| GB8523630D0 (en) * | 1985-09-25 | 1985-10-30 | Pena Ltd Paul De | Bioelectrochemical cell measurement |
| US4735691A (en) * | 1985-12-23 | 1988-04-05 | Allied Corporation | Method for operating electrochemical detector cell |
| EP0238322B1 (en) * | 1986-03-19 | 1992-02-26 | Paul De La Pena Limited | Mediators for bioelectrochemical cells |
| GB8608700D0 (en) * | 1986-04-10 | 1986-05-14 | Genetics Int Inc | Measurement of electroactive species in solution |
| US4963245A (en) * | 1986-05-02 | 1990-10-16 | Ciba Corning Diagnostics Corp. | Unitary multiple electrode sensor |
| JPH07122624B2 (en) * | 1987-07-06 | 1995-12-25 | ダイキン工業株式会社 | Biosensor |
| US4929426A (en) * | 1987-11-02 | 1990-05-29 | Biologix, Inc. | Portable blood chemistry measuring apparatus |
| US4863578A (en) * | 1988-04-25 | 1989-09-05 | Corrosion Service Company Limited | Corrodible link for cathodic protection systems |
| EP0353328A1 (en) * | 1988-08-03 | 1990-02-07 | Dräger Nederland B.V. | A polarographic-amperometric three-electrode sensor |
-
1988
- 1988-07-21 GB GB888817421A patent/GB8817421D0/en active Pending
-
1989
- 1989-07-18 AU AU38220/89A patent/AU622196B2/en not_active Ceased
- 1989-07-20 CA CA000606230A patent/CA1313397C/en not_active Expired - Fee Related
- 1989-07-21 US US07/383,202 patent/US5126034A/en not_active Expired - Lifetime
- 1989-07-21 EP EP93120044A patent/EP0593096A3/en not_active Withdrawn
- 1989-07-21 JP JP1187577A patent/JPH02112752A/en active Pending
- 1989-07-21 EP EP19890307463 patent/EP0352138A3/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| AU622196B2 (en) | 1992-04-02 |
| JPH02112752A (en) | 1990-04-25 |
| EP0593096A2 (en) | 1994-04-20 |
| US5126034A (en) | 1992-06-30 |
| AU3822089A (en) | 1990-02-01 |
| EP0593096A3 (en) | 1997-12-03 |
| EP0352138A3 (en) | 1990-11-07 |
| EP0352138A2 (en) | 1990-01-24 |
| GB8817421D0 (en) | 1988-08-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1313397C (en) | Disposable bioelectrochemical electrodes | |
| CA2167822C (en) | Potentiometric biosensor and the method for its use | |
| US6033866A (en) | Highly sensitive amperometric bi-mediator-based glucose biosensor | |
| US5656142A (en) | Biosensor for measuring gas and the manufacturing method thereof | |
| Ivnitski et al. | Application of electrochemical biosensors for detection of food pathogenic bacteria | |
| Lagarde et al. | Cell-based electrochemical biosensors for water quality assessment | |
| EP0484384B1 (en) | Piezoelectric cell growth biosensing method and system | |
| US6100045A (en) | Detection of analytes using electrochemistry | |
| Yoshida et al. | Improvement of a mediator-type biochemical oxygen demand sensor for on-site measurement | |
| KR20030038664A (en) | Electrochemical method for measuring chemical reaction rates | |
| Foster et al. | Electrochemical diagnostic strip device for total cholesterol and its subfractions | |
| Solé et al. | Determination of toxic substances based on enzyme inhibition. Part II. Electrochemical biosensors for the determination of pesticides using flow systems | |
| Tothill et al. | Monitoring of the glucose concentration during microbial fermentation using a novel mass-producible biosensor suitable for on-line use | |
| Cagnini et al. | Ruthenized screen-printed choline oxidase-based biosensors for measurement of anticholinesterase activity | |
| Hu et al. | Development of a mediator-type bioelectrochemical sensor based on polypyrrole immobilized ferricyanide and microorganisms for biochemical oxygen demand fast detection | |
| CN101825603A (en) | Current enzyme electrode for detecting catalase-positive bacteria and preparation method thereof | |
| Schaertel et al. | Biosensors in the food industry: present and future | |
| Richter | Biosensors: applications for dairy food industry | |
| Karube et al. | Immobilized cells used for detection and analysis | |
| EP0859229A1 (en) | Detection of analytes using electrochemistry | |
| Ramsay et al. | Rapid bioelectrochemical methods for the detection of living microorganisms | |
| Palchetti et al. | Amperometric biosensor for pathogenic bacteria detection | |
| CN115266865B (en) | Method for improving stability of electrochemical sensor | |
| Chunxiang et al. | Microbial sensor for on-line determination of microbial population in a fermenter | |
| Hu | Research and development of biosensors in China |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |