Electroless Plating Growth Au-Ag Core-Shell Nanoparticles for Surface Enhanced Raman Scattering

Abstract

Au core-Ag shell nanoparticles (NPs) have been grown on the silicon substrate with self-assembled well-define Au NPs by electroless plating method. The holding time of spin-coating strategy is a facile method for controlling the densities of Au NPs and treating them as an electrode for selective growth of Ag shell. The volumes of silver nitrate play an important role in growing the different shell thicknesses of Au-Ag core-shell NPs. The appropriate shell thicknesses and the densities of Au-Ag core-shell NPs were optimized to yield the greatest surface-enhanced Raman scattering (SERS) effect in rhodamine B molecule. The combination spin-coating strategy and electroless silver plating provide a facile and low cost fabrication method to prepare the different shell thicknesses and densities of Au-Ag core-shell NPs with high SERS enhancement, which shall be of significant value for practical applications of biosensor systems.