Research On Silver/Biomaterial SERS Substrate And Performance Optimization

Surface-enhanced Raman Scattering(SERS)is a spectroscopic technique that can reflect the unique spectral information of molecules.It has the advantages of high sensitivity,undamage analysis,and quick response,so it is extensively used in the research of food safety,environmental monitoring,biomedicine and other fields.In recent years,methods to improve the performance of SERS substrates by adjusting the size,distribution,and spacing of metal particles to increase the density of “hot spots”per unit laser area have received extensive attention.The preparation of SERS substrates with excellent performance by a simple and inexpensive method is an important prerequisite for its application in real life.This paper aims at the low-cost preparation and performance optimization of SERS substrates.The main research contents are as follows:Firstly,Ag films were modified on substrates with different structures and their SERS properties were investigated.Using wheat leaf as the substrate,the Ag film was modified on its micro-convex structure and flat structure by magnetron sputtering technology,and the morphology and size of the substrate were optimized by adjusting the sputtering time,and the most suitable nanostructure was found.And the density of “hot spots”was adjusted to obtain SERS substrates with different enhancement properties.The Raman spectrometer was used to screen the substrates and analyze the properties of the two SERS substrates with different structures.Secondly,Ag films were modified on irregularly structured substrates and their SERS properties were investigated.Taking razor clam as the substrate,it has a columnar nanostructure after removing the cuticle,and the Ag film is decorated on the substrate by magnetron sputtering.The surface plasmon resonance effect was obtained to obtain substrates with enhanced properties.The SERS performance of the optimal substrate was analyzed using Rhodamine 6G as a probe molecule.Finally,Ag NPs were modified on the original substrate to optimize the SERS performance of the substrate.The previously prepared Ag/razor clam was used as the substrate,and Ag NPs layer with a diameter of about 55 nm was added to the surface by self-assembly method,which changed the roughness of the substrate surface and effectively improved the amount of silver within the unit laser irradiation range.Density of “hot spots”in AgNPs/Ag/razor clam substrates.At the same time,Raman spectrometer and confocal Raman spectrometer were used to analyze the performance and performance optimization of substrate SERS.