Hydrothermal Preparation And SERS Of AuNS And Composite Structures

Surface-enhanced Raman scattering(SERS)detection technology has been widely used in biomedical detection,food safety detection and environmental pollution detection due to its ultra-high sensitivity,non-destructive testing and fast detection speed.How to prepare the performance of the SERS substrate is the key to the SERS detection technology.Gold nanosheets have become the most widely used materials in the SERS substrates of noble metal nanomaterials due to their good stability and uniformity,as well as the LSPR effect.The research on the enhancement mechanism of SERS is still not systematic,which has led to many controversies,and needs to be further explored through experiments and theory.The main research of this paper is as follows:(1)The surface of pure gold nanosheets(Au NS)was modified by polyol method,and Ag-Au NS composite structures with surface modification,particle modification and wire modification were obtained.Its SERS performance was studied.The results show that the three different surface composite structures have good performance in terms of sensitivity,stability and uniformity.At the same time,the hollow gold nanosheet(Ho GNS)structure was obtained by secondary growth around small-scale Au NS by epitaxial growth method.This study provides a new idea for the construction and preparation of Au NS and its composite structure SERS substrate.(2)Both the structural parameters of hollow gold nanosheets(Ho GNS)and the polarization direction of the incident wave electric field will affect their SERS performance.The optical properties of Ho GNS were investigated using finite difference time domain(FDTD).Taking the T-T Ho GNS as the model,the effects of the side length of the IHT,the thickness of the Ho GNS,the electric field polarization direction of the incident wave,the rotation angle of the IHT and the number of sides of the OT polygon on the LEF intensity at different points of the Ho GNS were investigated.This study provides an important theoretical basis and reference value for the design and construction of Ho GNS-based nanocomposites in the future.