Aromatic amino groups can be attached through different binding points to the surface. In a previous work, we have demonstrated that alpha-phenylglycine (PGly) interacts with a silver surface through its functional groups. In addition, a large charge-transfer (CT) contribution was found in the overall SERS intensification. In the present work we studied the SERS of PGly on Ag metal colloids prepared by different methods in order to investigate the influence of the chemical nature of the metal substrate on the adsorption and on the CT processes taking place between this amino acid and the metal. (C) 2007 Published by Elsevier B.V.