CN102706857A - Preparation method of multifunctional surface enhanced raman scattering (SERS) substrate - Google Patents

Abstract

The invention provides a preparation method of a multifunctional surface enhanced raman scattering (SERS) substrate. The preparation method comprises the following steps of: firstly, paving a layer of ZnO seeds on the inner wall of a capillary, developing a ZnO nanorod array in Zn(NO3)2 and hexamethylenetetramine (HMT) solution, and soaking and reacting the capillary in solution of (NH4)2TiF6 and H3BO3, thus obtaining a TiO2 nanotube array; and soaking a nanotube in which TiO2 is grown into SnCl2 to ensure that a layer of bivalent tin ions are adsorbed on the surface layer of the nanotube, soaking the nanotube into Ag(NH3)2+ and reducing the nanotube to silver particles, thus obtaining the multifunctional SERS substrate. Compared with the conventional SERS substrate, the multifunctional SERS substrate based on the capillary has functions of raman enhancement and repeated use, is convenient to carry and sample, and can realize real-time field detection.

Description

A kind of multifunction surface strengthens the preparation method of Raman scattering substrate

Technical field

The present invention relates to a kind of analysis and detection technology, be specifically related to a kind of Raman spectrum method for detecting surface reinforcement.

Background technology

Raman scattering is nineteen twenty-eight, tests in test discovery by India scientist C.V. Raman, thereby this phenomenon is called Raman scattering, is in brief: can be changed by occurrence frequency by the light of molecular scattering when light passes transparent medium.Raman spectrum is the same with infrared spectrum all be reflection molecular vibration-rotational energy level information, but the signal of Raman scattering very a little less than, its intensity only have 1,000,000 of incident intensity/, thereby do not paid attention to by scientific circles widely one period at the beginning of finding.Up to 1974; People such as Fleishmann are after carrying out roughened to smooth silver electrode surface; Obtain to be adsorbed on the high-quality Raman spectrum of unimolecular layer pyridine molecule on the silver electrode surface first, the Raman scattering signal of its intensity and the solution pyridine in is mutually compared, and strengthens about 6 one magnitude (promptly 1,000,000 times); This Raman enhancement effect relevant with rough surface is called as SERS (Surface Enhanced Raman Scattering, SERS) effect.From then on, SERS becomes a new research focus gradually.

After the SERS effect comes to light; Various have the SERS substrate of Raman reinforced effects constantly to be produced out; Have superpower Raman reinforced effects, the easy SERS substrate that is easy to get is the focus of research always; In recent years, various SERS substrates with different-shape structure constantly are studied personnel and make, although detectability reaches 10 ^-12-10 ^-14The SERS substrate of M has been studied personnel and has reported, but the preparation process of these SERS substrates is complicated, and equipment needed thereby is expensive, and can't reuse, and can cause the waste of energy resources, from practical a certain distance in addition, can only in the laboratory, exist.Though have the SERS substrate of higher enhancement effect is the target that Science Institute is pursued, and obtains a kind of more practical and cheap SERS substrate and seems more important.

Summary of the invention

1. invent the technical matters that will solve

The deficiency that the present invention overcomes prior art provide a kind of sampling make things convenient for, be easy to carry, reusable, can be used for the on-the-spot SERS substrate that detects with Raman enhancement effect.

2. technical scheme

In order to solve above technical problem, the present invention is achieved by the following technical programs.

A kind of multifunction surface strengthens the preparation method of Raman spectrum substrate, may further comprise the steps:

(1) constructs TiO at capillary tube inner wall ₂Nano-tube array: through with the layer overlay ZnO of capillary tube inner wall elder generation seed, at Zn (NO ₃) ₂With first growing ZnO nanorod arrays in the HMT solution, kapillary is dipped in (NH ₄) ₂TiF ₆And H ₃BO ₃Middle reaction can obtain TiO ₂Nano-tube array;

(2) again with silver-colored particle modification at TiO ₂The surface: will grow has TiO ₂Nanotube is dipped in SnCl ₂In make top layer absorption one deck divalent tin ion, again through it being dipped in Ag (NH ₃) ₂ ⁺In make it be reduced into silver-colored particle and obtain;

Utilize TiO ₂The Raman enhancement effect of the photocatalytic degradation function of nanotube and silver makes this substrate can be used as multi-functional SERS substrate.

The principles of science of the present invention is analyzed:

One, capillary tube inner wall is first with Zn (Ac) ₂Ethanolic solution handle, handle 20min down at 350 ℃, make capillary tube inner wall produce the layer of ZnO seed.There is the kapillary of ZnO seed to be dipped in Zn (NO inwall ₃) ₂And hexamethylene tetramine (HMT) solution can obtain the nanometer stick array of zinc paste 90 ℃ of down reactions, through at (NH ₄) ₂TiF ₆And H ₃BO ₃Middle reaction can obtain the nano-tube array of titanium dioxide.Because titania has the function of photocatalytic degradation, therefore, will produce photodegradative effect at the bottom of this SERS active group, thereby make it have the function that repeats can be recycled.

Two, in the titania nanotube finishing behind the silver-colored particle because silver has the SERS enhancement effect, promptly can produce Raman and strengthen, should have Raman enhancing and reusable function concurrently based on multi-functional SERS substrate capillaceous thereby make.

3. beneficial effect

Traditional SERS substrate is all constructed on the plane; When practical operation, need object solution to be measured be dripped in substrate with other instruments (like liquid-transfering gun), wait to do the back and under Raman spectrum, detect, its operation steps is more; Be inconvenient to carry, be inappropriate for on-the-spot the detection.The present invention is based on SERS substrate capillaceous because capillary action can not need the non-productive operation of other instruments, simultaneously because the inwall growth has one deck TiO ₂Array makes its performance with photocatalytic degradation, can realize the repeated use of SERS substrate, and required sample size few, be easy to carry, be convenient to sampling, can realize that real-time scene detects.

Description of drawings

Fig. 1 strengthens the technical scheme synoptic diagram of Raman substrate preparation method for the multi-functional capillary surface of the present invention.

Fig. 2 changes TiO into for the ZnO array ₂The scanning electron microscope of array (SEM) figure.

Fig. 3 is scanning electron microscope (SEM) figure of the nano-particle modified Nano tube array of titanium dioxide of Ag.

Fig. 4 is the Raman spectrogram behind absorption R6G in the multi-functional SERS substrate of the present invention.

Embodiment

Below in conjunction with accompanying drawing the present invention is further described.

As shown in Figure 1, multi-functional capillary surface strengthens Raman substrate preparation method and may further comprise the steps: A: at the method generation layer of ZnO seed of capillary tube inner wall with thermal decomposition, let kapillary at Zn (NO again ₃) ₂With HMT growth from solution ZnO array; B: change the ZnO array into TiO ₂Array; C: at TiO ₂The outer modification of nanotube gone up silver-colored particle.

Fig. 2 changes TiO into for the ZnO array ₂The scanning electron microscope diagram of array.It is made up of A, B, C, D four parts, wherein, and A: the nanometic zinc oxide rod array sem photograph of growing on a large scale; B: large-scale Nano tube array of titanium dioxide sem photograph; C: to the partial enlarged drawing of figure A, the nanometic zinc oxide rod array of visible proper alignment; D: to the partial enlarged drawing of figure B, can see Nano tube array of titanium dioxide neat grow in capillary tube inner wall.

Fig. 3 is scanning electron microscope (SEM) figure of the nano-particle modified Nano tube array of titanium dioxide of Ag.It is made up of A, B two parts, wherein, and A: the sem photograph of the Nano tube array of titanium dioxide of capillary tube inner wall silver particle modification; B: to the partial enlarged drawing of figure A, visible silver-colored particle is modified at the surface of titanium oxide nanotubes uniformly.

Below in conjunction with embodiment the present invention is done further description, but the present invention is not limited to following embodiment.

Embodiment 1

Construct TiO at capillary tube inner wall ₂Nano-tube array:

At first, it is inner to make the ethanolic solution of zinc acetate get into kapillary, and 60 degrees centigrade draw under the condition after the drying in baking oven, and annealing is 20 minutes under 350 degrees centigrade the condition, so just can make the seed of its inwall generation one deck zinc paste.Then, this kapillary is placed Zn (NO ₃) ₂With reacted 90 minutes down at 90 degree in the HMT solution, can be at the inwall layer of ZnO array of growing.The ZnO array is at (NH ₄) ₂TiF ₆And H ₃BO ₃The middle reaction 90 minutes just can obtain the nano-tube array of titanium dioxide.Fig. 2 A and C are respectively the SEM photos of the zinc oxide array under the different amplification, the visible interior on a large scale zinc oxide array that distributes; Fig. 2 B and D are the SEM photos that zinc paste is replaced into titanium dioxide.

Embodiment 2

With silver-colored particle modification at TiO ₂The surface:

Have the kapillary of titania nanotube array to be dipped in earlier in the inferior tin WS of dichloro of 0.05g/20mL growth, with the flushing of secondary water for several times, titania surface can be adsorbed one deck divalent tin ion like this after one hour.Be placed on again in the silver ammino solution of 1mmol/L, take out after 30 minutes, clean, can obtain the titania nanotube array of silver-colored particle modification, as shown in Figure 3.

Embodiment 3

Whether detect SERS substrate of the present invention possesses the Raman enhancing and reuses function:

In substrate, adsorb 10 ^-5Under Raman spectrometer, detect behind the R6G of mol/L (the chemistry rhodamine 6G by name) ethanolic solution; Can obtain stronger enhancing signal, and substrate is through after the photocatalytic degraded, the SERS blackout; Substrate still can be used after reusing 5 times, and signal does not have obviously and weakens.As shown in Figure 4,1～5 representes the signal behind the substrate absorption R6G respectively; The SERS signal of " light degradation " representative after the photocatalytic degraded can be found out the characteristic peak that has not had R6G.This substrate of more than experiment proof has the Raman enhancement function and possesses the organic function of catalytic degradation simultaneously, can recycle.

Claims (1)

1. a multifunction surface strengthens the preparation method of Raman scattering substrate, it is characterized in that may further comprise the steps:

(1) constructs TiO at capillary tube inner wall ₂Nano-tube array: through with the layer overlay ZnO of capillary tube inner wall elder generation seed, at Zn (NO ₃) ₂With first growing ZnO nanorod arrays in the HMT solution, kapillary is dipped in (NH ₄) ₂TiF ₆And H ₃BO ₃Middle reaction can obtain TiO ₂Nano-tube array;

(2) again with silver-colored particle modification at TiO ₂The surface: will grow has TiO ₂Nanotube is dipped in SnCl ₂In make top layer absorption one deck divalent tin ion, again through it being dipped in Ag (NH ₃) ₂ ⁺In make it be reduced into silver-colored particle and obtain;

Utilize TiO ₂The Raman enhancement effect of the photocatalytic degradation function of nanotube and silver makes this substrate can be used as multifunction surface and strengthens the Raman scattering substrate.

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