A kind of preparation method of surface-enhanced Raman substrate

Abstract

The invention discloses a method for preparing surface-enhanced Raman substrates. The method includes acquiring nanometer columnar array structures on substrates by the aid of nanometer imprinting processes; depositing metal on the nanometer columnar array structures to obtain metal nanometer finger array structures; depositing tetrahedral carbon films with the sizes of 1 nanometer on the metal nanometer finger array structures; dropwise adding high-purity ethyl alcohol solution on the metal nanometer finger array structures coated with the tetrahedral carbon films and volatilizing the high-purity ethyl alcohol solution under natural conditions to form metal nanometer finger closed array structures. The method has the advantages that metal nanometer fingers can be driven by capillary forceto collapse in ethyl alcohol volatilization procedures, and accordingly the metal nanometer finger closed array structures can be formed; controllable gaps with the sizes four times the thicknesses of the tetrahedral carbon films can be formed between the metal nanometer fingers, strong-coupling enhanced electric fields can be formed in gap regions, and accordingly surface-enhanced Raman detection can be carried out on single molecular levels.

Description

technical field [0001] The invention relates to a nanometer material, relates to testing or analyzing the material by means of measuring the chemical or physical properties of the material, and particularly relates to a preparation method of a surface-enhanced Raman substrate. Background technique [0002] Surface-Enhanced Raman Spectroscopy (SERS) technology has a wide range of applications in physics, chemistry, materials science, biomedicine and other fields. The enhancement principle is based on the resonant excitation of the surface plasmon effect of the metal nanostructure, thereby forming an enhanced electromagnetic field on the surface of the metal nanostructure, which greatly enhances the Raman signal of molecules located near the enhanced electromagnetic field on the metal surface. The enhancement factor of the signal is proportional to the fourth power of the enhanced electromagnetic field strength. Compared with other measurement methods, Raman detection has mol...

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Problems solved by technology

Continuing to reduce the gap size below 1-2 nm will lead to a weakening of the enhanced electric field

However, due to the limitation of processing precision, the size of the current gap has large fluctuations, which makes the distribution of the enhanced electric field different, which will cause fluctuations in the enhancement factor of surface-enhanced Raman, which is not conducive to the practical application of surface-enhanced Raman technology.

[0004] At present, based on the nano-metal particles in the solution, the gap between the particles can be controlled more accurately by the DNA method, and the size can be reduced to 1-2 nanometers. Large, unable to meet the actual needs, and the gap distribution in the solution is uncontrollable, it is impossible to accurately place the molecules to be measured in the coupling electromagnetic field area, and it is impossible to accurately realize Raman detection at the single-molecule level

However, for the metal nanoarray structure prepared based on nano-micro-processing technology, due to the limitation of precision, it is still unable to provide a surface-enhanced Raman substrate with high enhancement factor and good reproducibility, and it is also impossible to achieve Raman detection at the single-molecule level.

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