DE10228088B4 - Electrochemical sensor, as well as a method for producing the electrochemical sensor and its arrangement - Google Patents

Abstract

electrochemical Sensor (1) for determining components of in a channel (8) flowing Breathing condensate, consisting of a ceramic carrier (2) arranged working electrode (3) and reference electrode (4), which with connection contacts (6) are provided, wherein the working and the reference electrode (3, 4) each consist of several layer strips (5), wherein the Layer strip (5) of an electrode (3, 4) arranged like a comb are and the layer strips (5) of both electrodes (3, 4) with each other comb, and being over both electrodes (3, 4) across a water permeable biologically active coating (7) is arranged.

Description

The The invention relates to an electrochemical sensor with biological active coating for analyzing the constituents of the breath condensate.

electrochemical Sensors with biologically active coating for analysis of respiratory condensate are known. So is by the Radeberger hybrid electronics GmbH under the name DSE variant 22 a with a ceramic Support plate provided distributed electrochemical sensor whose reference electrode a three-quarter circular Layer exists, and at the center of the annulus as Full circle layer, the working electrode is arranged. The working electrode consists of platinum and the reference electrode of silver and silver chloride. Lead by the electrodes each conductor tracks to the acceptance contacts. On the electrodes is overarching a water-permeable biological active coating arranged. The disadvantage of this electrochemical Sensor consists in the small reaction surface.

This Problem is compounded when the sensor is measuring a sample medium flowing in a channel should.

In the work of Saum, A. G. E. [u. a] "Use of substrate coated electrodes and AC impedance spectroscopy for the detection of enzyme activity "(In: Biosensors & Bioelectronics, 1998, Vol. 13, pp. 511-518) is a biosensor for measuring aerosols disclosed in which two working electrodes mesh together like a comb.

The WO 02/29378 A2 describes a sensor with two interdigitated electrodes, both electrodes being either working electrodes only or reference electrodes only. For the simultaneous use of working and Referenzelektro the thus at least two sensors of different functions are necessary.

A similar sensor is the US script US 5,698,083 A can be seen in which also working and reference electrodes are arranged on different sensors. The reference electrode is not occupied with bioactive molecules unlike the working electrode.

Thick-film lead electrodes as biosensors in which the surface of the electrodes is occupied with enzymes are disclosed in the disclosure DE 41 32 441 A1 known.

A grid-like arrangement of sensors in which the working and reference electrodes are arranged in a ring reveals the EP 0 442 969 B1 ,

A biosensor with a biologically active layer, which is framed by an electrode, is the DE 44 08 352 A1 refer to.

The DE 100 18 959 A1 discloses a biosensor comprising an electrically insulating ceramic substrate on which a working and a reference electrode are formed with respective terminal contacts. On the working electrode and the reference electrode is disposed a reaction layer containing an enzyme, a carrier, an electrical medium and a surfactant. In addition, the biosensor still has an insulating layer and a mesh-like covering layer.

The DE 195 37 506 C1 teaches a biosensor that is integrated into a flow cell. The biosensor is designed as a flat element and has a working electrode with a biologically active layer, a reference electrode and contacts for electrical connections.

task The invention is the reaction surface of an electronic sensor with biologically active coating, so he in particular to measure flowing Samples can be used.

Is solved This object with the features of claim 1, a method for the preparation describes claim 12 and a preferred arrangement is presented with claim 15. Advantageous embodiments are Subject of the dependent claims.

Of the Inventive electrochemical sensor for determining constituents of respiratory condensate flowing in a channel consists of on a ceramic carrier arranged working electrode and reference electrode over the cross one water-permeable biologically active coating is arranged, and provided with terminal contacts are, wherein the working and the reference electrode each of several Layer strips consist, wherein the layer strips of an electrode arranged comb-like and the layer strips of both electrodes then comb with each other.

The Comb the layer strip of the working and the reference electrode extends is preferred over a section of the length of the channel, wherein the layer strips of the working and the reference electrode across, along or at an angle to the flow direction the breathing condensate can be arranged.

The biologically active coating is preferably a mixture made of polyurethane, enzyme and redox mediator.

Of the Advantage of this electrochemical sensor is that the Measurement is extended even with small sample quantities and can be evaluated Results.

In A further advantageous embodiment provides that several sensors arranged in parallel or series arrangement on a ceramic carrier are, so they can be successively or simultaneously, if necessary with little delay from the pouring Breathing condensate can be contacted. The biologically active coating these sensors may be the same or different, different in particular by using different enzymes and / or Redox mediators.

Known is a process for the production of electrochemical sensors, in which the layout of a variety of sensors grid-like on one ceramic carrier is applied, in which a separation of the ceramic carrier in Single sensors takes place in the electrodes of an electrochemical Be subjected to treatment and biologically on the sensors active layers are arranged.

By the sensor according to the invention, the layout of each arranged from comb-like layer strips of working and reference electrodes, connection contacts for the electrodes as well as connecting conductors between the electrodes and the connection contacts exists, with the stratigraphy of working and reference electrodes comb each other, Now there are the prerequisites, this procedure to the effect to improve that with the application of the layout of the sensors on the common ceramic carrier or subsequently in each case an electrically conductive connection between the produced by electrochemical treatment electrodes to be modified will, the entire ceramic carrier subjected to the electrochemical treatment, according to appropriate Purification and pretreatment of the biologically active layer over the Electrodes across each sensor is applied, and a separation of the ceramic carrier in individual sensors under destruction the connection between the electrodes of different sensors takes place.

there are electrodes in the grid of adjacent sensors for the electronic Treatment, such as the reference electrodes, which consist of applying the layout of silver and electrolysis superficially in Silver chloride to be converted. This simplifies the conventional one Technology essential.

These Technology can be applied analogously if multiple sensors on a ceramic carrier should be arranged.

The Arrangement of the or the electrochemical sensors with biological active coating for the analysis of the constituents of the breath condensate takes place via a Sensor side open channel, which is flowed through by the respiratory condensate.

Of the Channel can be as described on the length of the channel sensor side open be or there is a fanning of the channel into individual arms, which in turn are opened on the sensor side. The opening of the Channels or arms can be continuous or separate for each sensor be. The fan-out can be in parallel, star-shaped or radiating or combinations of arms arranged therefrom.

One such channel is in an advantageous embodiment in a closed Arranged cassette, wherein the cassette contains reservoir with solutions for flush and / or solutions to Conditioning the sensor and / or with solutions for calibration and / or with substances for the preparation of a calibration solution and / or for dilution of the sample solution and / or to increase the ion concentration or the conductivity of the sample solution, wherein the reservoir by means of the outside through the cassette walls interact with them, their contents completely or metered into the channel and thus on the sensor and the cassette over at least an opening for introducing the sample solution in the channel and thus has the sensor.

The sensor-side opening or the openings the channel or the arms of the channel are preferred as a longitudinal slot ausgebil det and be by the or the sensors used then completely locked. The sensor or sensors can do so via the sensor-side opening or the openings of the channel or its arms are glued or inserted into the cassette and thus over the sensor-side opening or the openings be formed of the channel or its arms.

In a preferred embodiment is the sensor-side opening of the channel or its arms as a breakthrough or breakthroughs through the outer wall of the Cassette formed and are closed by the one or more sensors.

The Invention will be explained in more detail with reference to the drawings. Show it:

1 : Sensor variant A,

2 : Sensor variant B (not according to the invention),

3 : several sensors on a ceramic carrier,

4 : Manufacture of sensors,

5 : several sensors in series on one channel

6 : several sensors on a channel shared in parallel arms and

7 : Sensors on channel and star-shaped arms

8th : Arrangement of a sensor on a measuring cassette.

1 shows a variant A of an electrochemical sensor 1 for determining constituents of in one channel 8th flowing breath condensate coming from a on a ceramic carrier 2 arranged working electrode 3 and a reference electrode 4 there is, across the over a water-permeable biologically active coating 7 is arranged. The working and the reference electrode 3 . 4 each consist of several layers of stripes 5 together, which are comb-like arranged and the layer strips 5 both electrodes 3 . 4 comb each other. Furthermore, the working and the reference electrode 3 . 4 with connection contacts 6 Mistake. The working electrode 3 consists of platinum and the reference electrode 4 made of silver and silver chloride. The biologically active coating 7 is composed of a mixture of polyurethane, enzyme and TTF.

The combing of the layer strips 5 the working and the reference electrode 3 . 4 extends essentially over the sensor 1 open length of the canal 8th , where the layer strips 5 the working and the reference electrode 3 . 4 are arranged transversely to the flow direction of the breath condensate.

In 2 is a not inventive variant B of the sensor 1 presented in which the layer strips 5 the working and the reference electrode 3 . 4 are arranged longitudinally to the flow direction of the breath condensate. The working electrode 3 consists here of a layer strip 5 that between two layer strips 5 the reference electrode 4 is arranged.

3 shows an arrangement of several sensors 1a -D on a ceramic carrier 2 in a row over the canal 8th , The channel 8th is here consistently provided with a sensor-side opening, ie the opening has z. B. a length of the ceramic carrier 2 , It is also possible that the channel 8th has a separate opening for each sensor. The sensors 1a -D are overflowed in succession from the respiratory condensate. The combing of the layer strips 5 the respective working and reference electrodes 3 . 4 extends substantially over the to the sensors 1a -D out each open length of the channel 8th , where the layer strips 5 are arranged transversely to the flow direction of the breath condensate. Of course, an arrangement of the layer strips is also possible obliquely or in the longitudinal direction to the flow direction of the breath condensate. Furthermore, this arrangement offers the possi bility of reference electrodes 4 the sensors 1a -D to connect with each other.

The 4a and 4b show the arrangement of the layout of a variety of sensors 1 grid-like on a ceramic support 2 applied in the process of manufacture. The layout of each sensor 1 consists of comb-like layer strips 5 of working and reference electrodes 3 . 4 , Connection contacts 6 for the electrodes as well as connecting conductors between the electrodes and the terminal contacts, wherein the layer strips 5 of working and reference electrodes 3 . 4 comb each other. By applying the layout of the sensors 1 on the common ceramic carrier 2 each was an electrically conductive connection between the reference electrodes 4 in the grid of adjacent sensors 1 prepared for electrochemical treatment.

The entire ceramic carrier 2 can be subjected to the electrochemical treatment by electrolysis, wherein the silver of the reference electrodes 4 is superficially converted into silver chloride. After appropriate cleaning and pretreatment, the biologically active layer 7 each via the electrodes 3 . 4 are applied across and then takes place a separation of the ceramic carrier 2 in individual sensors 1 by destroying the connection 9 ,

This technology is also applicable when using multiple sensors 1a -D on a ceramic carrier 2 to be ordered. In 3 this is at the "broken" ends of the reference electrodes 4 on the edge of the ceramic carrier 2 indicated. The dividing lines 9 for the ceramic carriers 2 need only be adjusted accordingly.

The 5 to 7 show the arrangement of the sensors 1a -D in the longitudinal direction of the canal 8th and a channel fanned out in arms 8th , respectively via openings of the channel 8th or his arms. The fanning can be done in parallel, star-shaped or radially arranged arms, the arms also at an angle to the channel 8th can be arranged. While at 5 the sensors 1a -D are successively overflowed by the respiratory condensate, this takes place at the fanned-out channel 8th of the 6 delayed in time and the star-shaped fanned channel 8th to 7 simultaneously. The fanned arms of the channel 8th be after the Measuring points brought together again.

Such arrangements of the sensors 1 and 1a -D provide along with the training of the sensors 1 and 1a -D of intermeshing strata 5 of working and reference electrode 3 . 4 the ability to extend the measurement even with small amounts of sample even further and to measure different components when using different sensors.

The 8a shows the arrangement of the electrochemical sensor 1 with biologically active coating 7 for analyzing the constituents of the respiratory condensate over a channel open on the sensor side 8th , which is flowed through by the condensate condensate. The channel 8th is in a closed cassette 10 arranged, the reservoir with solutions for flushing and / or with solutions for conditioning of the sensor 1 and / or with solutions for calibration and / or with substances for producing a calibration solution and / or for diluting the sample solution and / or for increasing the ion concentration or the conductivity of the sample solution, wherein the reservoir by means of the outside through the cassette walls on they interact, their contents completely or metered into the canal 8th and thus on the sensor 1 submit. Furthermore, the cassette has 10 over at least one opening 11 for introducing the sample solution into the channel 8th and thus on the sensor 1 , As in 8b shown is the sensor-side opening of the channel 8th as a longitudinal slot and breakthrough through the outer wall of the cassette 10 trained and then by the sensor 1 completely closed. This can be done conveniently by gluing.

But it is also possible, the sensor 1 as a slot in the cassette 10 and thus over the sensor-side opening of the channel 8th train.

Of course, in such a cassette 10 also with several sensors 1a -D be worked, with the channel 8th having one of the aforementioned training.

1

sensor

2

ceramic carrier

3

working electrode

4

reference electrode

5

layer strip

6

terminals

7

biological active coating

8th

channel

9

connection

10

cassette

11

opening

12

parting line

Claims (23)

Electrochemical sensor ( 1 ) for determining constituents of in a channel ( 8th ) flowing breath condensate, consisting of a ceramic carrier ( 2 ) arranged working electrode ( 3 ) and reference electrode ( 4 ), which with connection contacts ( 6 ), wherein the working and the reference electrode ( 3 . 4 ) each of several layer strips ( 5 ), the layer strips ( 5 ) of an electrode ( 3 . 4 ) are arranged comb-like and the layer strips ( 5 ) of both electrodes ( 3 . 4 ) and with both electrodes ( 3 . 4 ) across a water-permeable biologically active coating ( 7 ) is arranged. Electrochemical sensor according to claim 1, characterized in that the combing of the layer strips ( 5 ) of the working and the reference electrode ( 3 . 4 ) over a length of the channel ( 8th ). Electrochemical sensor according to claim 1 or 2, characterized in that the layer strips ( 5 ) of the working and the reference electrode ( 3 . 4 ) are arranged transversely to the flow direction of the breath condensate. Electrochemical sensor according to claim 1 or 2, characterized in that the layer strips ( 5 ) of the working and the reference electrode ( 3 . 4 ) are arranged longitudinally to the flow direction of the breath condensate. Electrochemical sensor according to claim 1 or 2, characterized in that the layer strips ( 5 ) of the working and the reference electrode ( 3 . 4 ) are arranged obliquely to the flow direction of the breath condensate. Electrochemical sensor according to one of claims 1 to 5, characterized in that the biologically active coating ( 7 ) consists of a mixture of polyurethane, enzyme (s) and redox mediator (s) or polyurethane and enzyme (s). Electrochemical sensor according to one of claims 1 to 6, characterized in that a plurality of sensors ( 1a -D) in parallel or series arrangement on a ceramic carrier ( 2 ) are arranged, so that they successively or simultaneously from in the channel ( 8th ) flowing breath condensate are contacted. Electrochemical sensor according to claim 7, characterized in that the sensors ( 1a -D) with a slight delay in the channel ( 8th ) flowing breath condensate are contacted. Electrochemical sensor according to claim 7 or 8, characterized in that the biologically active coating ( 7 ) of the sensors ( 1a -D) is the same or different. Electrochemical sensor according to claim 9, characterized in that the biologically active coating ( 7 ) of the sensors ( 1a -D) is different by using different enzymes and / or redox mediators. Electrochemical sensor according to one of claims 7 to 10, characterized in that reference electrodes ( 4 ) of the sensors ( 1a -D) are interconnected. Process for the preparation of electrochemical Sensors according to claim 1, wherein the layout of a plurality of Sensors is applied grid-like on a ceramic carrier, in which a separation of the ceramic carrier takes place in individual sensors, wherein the electrodes of an electrochemical Be subjected to treatment, and in which on the sensors biological active layers are arranged, characterized in that the layout of each sensor made of comb-like layer strips of working and reference electrodes, connection contacts for the electrodes as well as connecting conductors between the electrodes and the connection contacts exists, with the stratigraphy of working and reference electrodes comb each other, with applying the layout of the sensors to the common ceramic carrier or each followed by an electrically conductive connection between the produced by electrochemical treatment electrodes to be modified will, the entire ceramic carrier subjected to the electrochemical treatment, according to appropriate Purification and pretreatment of the biologically active layer over the Cross-electrodes is applied, and separating the ceramic carrier in individual sensors or Sensor groups under destruction the connection between the electrodes of different sensors or groups of sensors. Method according to claim 12, characterized in that that electrodes in the grid of adjacent sensors for the electrochemical Treatment be linked together. Method according to claim 12 or 13, characterized that the reference electrodes are made of silver when applying the layout exist, be connected to each other and superficially by electrolysis in Silver chloride to be converted. Arrangement for analyzing the constituents of the respiratory condensate, wherein the electrochemical sensor ( 1 ) according to claim 1 or the sensors ( 1a -D) according to claim 7 with biologically active coating ( 7 ) above a sensor-side open channel ( 8th ), which is permeated by the respiratory condensate, is / are arranged. Arrangement according to claim 15, characterized in that the opening of the channel ( 8th ) for the sensors ( 1a -D) continuously or for each sensor ( 1a -D) is formed individually. Arrangement according to claim 15, characterized in that the channel ( 8th ) is fanned out in parallel, star-shaped or radially extending arms or combinations thereof and the arms have sensor-side openings for analyzing the constituents of the respiratory condensate. Arrangement according to claim 17, characterized in that the parallel, star-shaped or radiating arms of the channel ( 8th ) at an angle to the inflow of the channel ( 8th ) are arranged. Arrangement according to one of claims 15 to 18, characterized in that the channel ( 8th ) in a closed cassette ( 10 ) is arranged and the cassette ( 10 ) Storage container containing solutions for rinsing and / or with solutions for conditioning the sensor ( 1 ) and / or with solutions for calibration and / or with materials for producing a calibration solution and / or for diluting the sample solution and / or for increasing the ion concentration or the conductivity of the sample solution, wherein the reservoir by means of the outside through the cassette walls on they act, their contents completely or metered into the channel ( 8th ) and thus on the sensor ( 1 ) and the cassette ( 10 ) via at least one opening ( 11 ) for introducing the sample solution into the channel ( 8th ) and thus on the sensor ( 1 ). Arrangement according to one of claims 15 to 19, characterized in that the sensor-side opening of the channel ( 8th ) or the sensor-side opening of the arms of the channel ( 8th ) are formed as longitudinal slots and through the sensor ( 1 ) or the sensors ( 1a -D) are completely closed. Arrangement according to one of claims 15 to 20, characterized in that the sensor ( 1 ) or the sensors ( 1a -D) via the sensor-side opening of the channel ( 8th ) or via the sensor-side openings of the arms of the channel ( 8th ) are glued. Arrangement according to one of claims 15 to 21, characterized in that the sensor ( 1 ) or the sensors ( 1a -D) as a slot in the cassette ( 10 ) and thus via the sensor-side opening of the channel ( 8th ) or the arms of the channel ( 8th ) is trained. Arrangement according to one of claims 15 to 22, characterized in that the sensor-side opening of the channel ( 8th ) or the sensor-side openings of the arms of the channel as a breakthrough through the outer wall of the cassette ( 10 ) are formed and by the sensor ( 1 ) or the sensors ( 1a -D) are closed.