Adsorption of sulfamethoxazole molecule on silver colloids: A joint SERS and DFT study

FTIR/ATR, FT-Raman and surface-enhanced Raman scattering (SERS) spectroscopic techniques, as well as density functional theory (DFT) calculations were used in order to characterize the sulfamethoxazole (SMX) molecule. Particular emphasis was put on the adsorption geometry of the molecule to the silver colloidal nanoparticles surface. FTIR/ATR, FT-Raman, Raman aqueous solution and SERS spectra of SMX were assigned based on DFT calculations with the hybrid B3LYP exchange–correlation functional, coupled with the standard 6-31G(d) basis set. Calculations performed on the SMX molecule adsorbed on a slab constructed to model the Ag(1 1 1) surface give quantitative results related to the geometry of the molecule in the vicinity of the silver surface.