CHARGE-TRANSFER CONTRIBUTION TO SURFACE-ENHANCED RAMAN-SCATTERING ANDSURFACE-ENHANCED RESONANCE RAMAN-SCATTERING OF DYES AT SILVER AND GOLD ELECTRODES

The charge transfer (CT) contribution to surface-enhanced Raman scatte ring (SERS) and surface-enhanced resonance Raman scattering (SERRS) wa s compared for several dyes adsorbed at silver and gold electrodes. It was found that the CT effect is more pronounced for dyes that in solu tion are not in resonance with the incident light (SERS spectra). For SERRS spectra the CT contribution seems to be negligible or considerab ly smaller in comparison with SERS. This means that the potential chan ges of the SERRS intensity reproduce the changes in surface concentrat ion more adequately than SERS.