Tunable surface plasma resonance frequency in Ag core/Au shell nanoparticles system prepared by laser ablation

A method for preparation of Ag core/Au shell nanoparticles with tunable surface plasma resonance (SPR) band was presented and studied. It was found that the tunable SPR band could be significantly conducted and achieved by laser ablation to Au plate in Ag colloidal solution, leading to the formation of Ag core/Au shell structure by the deposition of Au atoms on the surface of Ag nanoparticles. Dependence of the tunable shift of SPR bands on Ag core/Au shell structure was further illustrated by simulation of absorption spectra based on Mie theory, and consistent with the experimental results. (c) 2008 American Institute of Physics.