Theoretical study the surface-enhanced Raman scattering spectra of Thiophenol absorbed on Ag nanoparticles

摘要

Surface-enhanced Raman scattering (SERS) is a powerful spectroscopic technique for highly sensitive molecular detection. It effectively improves the defect of low sensitivity of normal Raman spectra. So it is widely used in the area of surface science, analytical science, biological science and so on. Using density functional theory (DFT) and Time-Dependent density functional theory (TD-DFT), the SERS spectrum has been simulated for biphenyl 1-4, 4'-dithiol (BPDT, HS-(C_6H4)_2-SH), p-terphenyl-4, 4"-dithiol (TPDT, HS - (C_6H_4)_3-SH ) 1, 4-benzenedithiol (BDT) absorbed on AuNPs and AgNPs. The SERS which aroused by C-C stretching mode is increasing with the benzene ring. Whereas, for the SERS of S-H bending vibrational mode, changing the position of S atom have little effect. The C-S stretching mode and S-H stretching mode are also little effect by the insert number.