The nature of the background emission in surface enhanced Raman scattering is elucidated. A simple group of benzene ring based thiols is used to demonstrate the introduction of optically active interface states upon adsorption on Ag coated dielectric core nanowires. Excellent agreement is obtained with density of state (DOS) calculations for benzenethiol adsorbed on Ag. We also present evidence for photoluminescence enhanced resonant Raman scattering as an important component of surface enhanced Raman scattering. (C) 2009 Elsevier B. V. All rights reserved.