CN106404738A - Graphene oxide/silver nanoparticle/pyramid-shaped silicon three-dimensional Raman enhanced substrate and preparation method and application thereof - Google Patents

Abstract

The invention provides a graphene oxide/silver nanoparticle/pyramid-shaped silicon three-dimensional Raman enhanced substrate and its preparation method and application; the pyramid-shaped silicon substrate is prepared by a wet etching process, and the silver nanoparticle solution is coated on the surface of the silicon substrate. Afterwards, the graphene oxide solution is coated on the surface of silver nanoparticles/pyramid-shaped silicon and baked; the preparation method is simple to operate, non-toxic and pollution-free, and cumbersome steps are omitted; and the three-dimensional Raman-enhanced substrate prepared by this method Combining graphene oxide, silver nanoparticles and pyramid-shaped silicon, the advantages of the three can be fully utilized to obtain Raman-enhanced signals with high sensitivity, good stability, and high uniformity; the key is that this is the first time that graphite oxide-based Preparation of ene/silver nanoparticles/pyramidal silicon composite three-dimensional Raman-enhanced substrates.

Description

A three-dimensional Raman-enhanced substrate of graphene oxide/silver nanoparticles/pyramidal silicon And preparation method and application

technical field

The invention belongs to the field of Raman detection, and relates to a graphene oxide/silver nanoparticle/pyramid silicon three-dimensional Raman enhanced substrate, a preparation method and an application.

Background technique

As a label-free analysis and detection method, Raman-enhanced technology has attracted extensive attention of researchers in recent years due to its extremely high sensitivity. Researchers have done a lot of work to obtain Raman-enhanced substrates with high sensitivity, good stability, and uniform stability. Studies have shown that the three-dimensional Raman-enhanced substrate has a larger specific surface area than the two-dimensional enhanced substrate, so the number of hot spots can be increased, and it is very conducive to the adsorption of the molecules to be measured, so a highly sensitive Raman-enhanced signal can be obtained . At present, three-dimensional Raman-enhanced substrates are mainly obtained by photolithography. The preparation process of this method is relatively cumbersome, the production cost is high and the efficiency is not high, which limits its development.

A single metal as a Raman-enhanced substrate material can obtain a certain Raman-enhanced effect, but its electromagnetic enhancement effect is limited, the sensitivity is limited, and the metal surface is easily oxidized, and the stability of the Raman-enhanced signal is not good.

Contents of the invention

The purpose of the present invention is to solve the above problems, and to provide a three-dimensional Raman-enhanced substrate based on graphene oxide/silver nanoparticles/pyramidal silicon, as well as its preparation method and application. The invention has simple operation and low cost, can realize the batch preparation of the three-dimensional Raman enhanced substrate, and the obtained Raman enhanced signal has high sensitivity, good stability and high uniformity.

In order to achieve the above object, the present invention adopts the following technical solutions:

A graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate, the enhanced substrate sequentially includes a pyramidal silicon substrate, a silver nanoparticle layer and a graphene oxide layer from bottom to top.

Three-dimensional pyramid-shaped silicon has a periodic surface structure and a large specific surface area, which can increase the number of hot spots and improve the sensitivity of Raman enhancement; compared with other metal particles, silver nanoparticles have higher sensitivity, and the surface is not easily oxidized. Stability can be solved by the graphene oxide layer; and graphene oxide also has the advantages of good biocompatibility and high chemical stability, and the functional groups existing on its surface are easier to achieve specific modification on its surface, so as to achieve biological Specific detection of molecules.

A preparation method of graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate, comprising the following steps:

(1) Grinding and pre-treating the substrate material to prepare a pyramid-shaped silicon substrate; (2) coating the silver nanoparticle solution on the pyramid-shaped silicon substrate; (3) continuing to coat the graphene oxide solution and baking to obtain the product. For the first time, the preparation of graphene oxide/silver nanoparticles/pyramidal silicon composite three-dimensional Raman-enhanced substrate was realized.

Further, the silicon base material is single crystal silicon.

Further, the method for preparing the pyramid-shaped silicon substrate in the step (1) is a wet etching process.

Further, the silver nanoparticle solution in the step (2) is a dispersion of silver nanoparticles with uniform diameter.

Preferably, the diameter of the silver nanoparticles is 5-50nm.

Further, the process of coating the graphene oxide solution in the step (3) is an immediate dip-coating method.

Application of the three-dimensional Raman-enhanced substrate prepared above in obtaining molecular Raman-enhanced spectra.

Beneficial effects of the present invention: (1) The present invention realizes the preparation of a three-dimensional Raman-enhanced substrate based on graphene oxide/silver nanoparticles/pyramidal silicon for the first time.

(2) The preparation method of the present invention is simple to operate, saves cumbersome steps, is non-toxic and pollution-free, and can realize batch preparation of three-dimensional Raman-enhanced substrates.

(3) The pyramid-shaped silicon of the present invention has a periodic surface structure with a large specific surface area, which increases the number of hot spots and improves the sensitivity of Raman enhancement. Easy to cut and functional modification; the combination of graphene oxide and silver nanoparticle layer, on the one hand, protects the oxidation of the silver nanoparticle layer, on the other hand, due to the good biocompatibility and high chemical stability of graphene oxide, it is very beneficial The adsorption of biomolecules, and because of the functional groups on its surface, graphene oxide is easier to realize the specific modification of its surface, so that the specific detection of biomolecules can be realized.

(4) The graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate provided by the present invention effectively combines the advantages of graphene oxide, silver nanoparticles and pyramidal silicon, and the Raman enhanced signal obtained High sensitivity, good stability and high uniformity.

Description of drawings

Fig. 1 is the schematic diagram that the present invention prepares graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate;

Fig. 2 is the scanning electron microscope image of graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate prepared in Example 1 of the present invention;

Fig. 3 is the graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate that the embodiment 1 of the present invention prepares and obtains the Raman enhanced spectrum of R6G molecule;

Fig. 4 is the Raman enhanced spectrum of adenosine molecule obtained from the graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate prepared in Example 2 of the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments. The materials can be obtained from public commercial sources unless otherwise specified.

Example 1

A graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate, the enhanced substrate sequentially includes a pyramidal silicon substrate, a silver nanoparticle layer and a graphene oxide layer from bottom to top. Its preparation method comprises the following preparation steps:

1. The surface of monocrystalline silicon is treated by wet etching process to obtain a pyramid-shaped silicon substrate;

2. Coating a uniform silver nanoparticle dispersion with a diameter of 5 nm onto the silicon-based surface to obtain a silver nanoparticle/pyramidal silicon surface;

3. Immediately dip-coat the graphene oxide dispersion onto the surface of silver nanoparticles/pyramidal silicon;

4. Baking treatment to obtain graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate.

Example 2

A graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate, the enhanced substrate sequentially includes a pyramidal silicon substrate, a silver nanoparticle layer and a graphene oxide layer from bottom to top. Its preparation method comprises the following preparation steps:

1. The surface of monocrystalline silicon is treated by wet etching process to obtain a pyramid-shaped silicon substrate;

2. Coating a uniform silver nanoparticle dispersion with a diameter of 50nm to the silicon-based surface to obtain a silver nanoparticle/pyramidal silicon surface;

3. Immediately dip-coat the graphene oxide dispersion onto the surface of silver nanoparticles/pyramidal silicon;

4. Baking treatment to obtain graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate.

The schematic diagram of the method for preparing graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman-enhanced substrate is shown in Figure 1. Fig. 2 is the scanning electron microscope image of the graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate prepared by the embodiment of the present invention, as can be seen from this figure: (1) the prepared three-dimensional enhanced substrate has a typical pyramid (2) Successfully realized the composite of graphene oxide, silver nanoparticles and pyramidal silicon.

Example 3

The graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman-enhanced substrate prepared in Example 1 was used to obtain the Raman-enhanced spectrum of R6G molecules.

Fig. 3 is the Raman-enhanced spectrum of R6G molecule obtained by the graphene oxide/silver nanoparticle/pyramid-shaped silicon three-dimensional Raman-enhanced substrate prepared by the present invention. , Raman-enhanced spectra of R6G molecules with good stability and high uniformity.

Example 4

The graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate prepared in Example 2 was used to obtain the Raman enhanced spectrum of adenosine molecules.

Fig. 4 is the Raman-enhanced spectrum of the adenosine molecule obtained by the graphene oxide/silver nanoparticle/pyramid-shaped silicon three-dimensional Raman-enhanced substrate prepared by the present invention. It can be seen from this figure that the sensitivity is obtained by using the prepared three-dimensional Raman-enhanced substrate Raman-enhanced spectra of high, stable, and homogeneous adenosine molecules.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (8)

1. A graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate, said enhanced substrate comprises a pyramidal silicon substrate, a silver nanoparticle layer and a graphene oxide layer from bottom to top. 2. a preparation method of graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate, is characterized in that, comprises the following steps: (1) Grinding and pre-treating the substrate material to prepare a pyramid-shaped silicon substrate; (2) coating the silver nanoparticle solution on the pyramid-shaped silicon substrate; (3) continuing to coat the graphene oxide solution and baking to obtain the product. 3. the preparation method of a kind of graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate as claimed in claim 2, is characterized in that, described silicon substrate material is single crystal silicon. 4. the preparation method of a kind of graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate as claimed in claim 2, is characterized in that, the method for described step (1) preparation pyramidal silicon substrate is wet corrosion process. 5. the preparation method of a kind of graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate as claimed in claim 2, is characterized in that, described step (2) silver nanoparticle solution is the uniform silver of diameter dispersion of nanoparticles. 6. the preparation method of a kind of graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman enhanced substrate as claimed in claim 5, it is characterized in that, the diameter of described silver nanoparticle is 5-50nm. 7. the preparation method of a kind of graphene oxide/silver nanoparticles/pyramidal silicon three-dimensional Raman enhanced substrate as claimed in claim 2, is characterized in that, in the described step (3), the process of graphene oxide solution coating For the instant dip-coating method. 8. The application of the graphene oxide/silver nanoparticle/pyramidal silicon three-dimensional Raman-enhanced substrate according to claim 1 or 2 in obtaining molecular Raman-enhanced spectra.