Examination of the Relationship Between SERS Intensities and Surface Concentration for Pyridine Adsorbed at the Gold/Aqueous Solution Interface.

摘要

Understanding the relationship between surface enhanced Raman scattering and surface concentrations of molecules is essential to gaining an understanding of the mechanism of SERS. At the metal/solution interface very few such studies have been reported. Here we present SERS data for pyridine adsorbed at the polycrystalline gold/aqueous solution interface, for which we also have data for surface coverage. SERS data for both smooth and rough electrode surfaces are presented. Chronocoulometry has been used to obtain reliable surface concentration data for pyridine adsorbed at the polycrystalline gold/aqueous solution interface. SERS data for both smooth and rough electrode surfaces have also been collected. Raman intensities of the 1010 cm-1 band of pyridine, measured for various bulk pyridine concentrations, track the surface concentration data very well for surface concentrations less than 3.2 x 10-10 mol cm-2. The SERS data for roughened gold electrode surfaces do not correspond well to the surface concentration data. SERS generates strong signals at cathodic potentials for which the surface concentrations are small on smooth gold electrodes. Keywords: Surface enhanced raman scattering; Pyridine on smooth gold electrodes; Electrochemical and spectroscopic data correlated; Surface roughness considered.