Preparation method of surface enhanced Raman scattering substrate

Abstract

The invention discloses a preparation method of a surface enhanced Raman scattering substrate. The method comprises the following specific steps: depositing metal gallium with an equivalent thicknessof 100 nanometers on the surface of a cleaned silicon wafer by using an electron beam evaporation technology, wherein the substrate temperature is 50 DEG C, and the vacuum degree is 4x10<-4>PA; placing a sample into a muffle furnace after the deposition, and annealing in an air atmosphere at the annealing temperature 400 to 500 DEG C for 4 to 5 minutes, wherein after the reaction, a large number of solid nanoscale gallium oxide particles are grown on the surface of the silicon wafer; and then depositing a layer of silver, gold or copper film on the surface by heat evaporation or ion sputteringto obtain a rough metal surface which can be used as the surface enhanced Raman scattering substrate. According to the preparation method, the non-infiltration characteristic of liquid gallium on thesilicon wafer is used for preparing a template with a rough surface, and the surface roughness can be changed by changing the deposition parameters of gallium or annealing conditions, thus changing the surface enhanced Raman scattering effect of the substrate.

Description

technical field [0001] The invention relates to the technical field of Raman scattering, in particular to a method for preparing a surface-enhanced Raman scattering substrate. Background technique [0002] Surface-enhanced Raman scattering is a kind of molecular adsorption on the rough metal surface, using the interaction mechanism between incident photons and nanoparticle surface valence electrons, to excite high-energy surface plasmons, and the high-energy "hot spots" formed by the surface plasmons act on the surface. The surface-sensitive technique of enhancing Raman scattering signal is a powerful analytical technique because it can greatly enhance the weak Raman signal, and it is simple and easy to use in biological and chemical detection. It has been found that the metals that can produce Raman enhancement effect include silver, gold and copper and other few metals, and the enhancement effect of silver is the best and most commonly used. [0003] The traditional surfa...

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Problems solved by technology

[0003] The traditional surface-enhanced Raman scattering substrate is to use electrochemical, ion etching, nano-lithography, template method, thermal evaporation method to prepare the above rough metal substrate, the method is too complicated and the cost is too high

The commonly used measurement method is to mix a certain concentration of the analyte with the above-mentioned metal nanoparticle solution. The advantage is that the method is simple and the Raman signal is significantly enhanced. However, the aggregation of metal particles often leads to poor repeatability of the measurement results.