Facile fabrication and raman scattering enhancement properties of mixed gold and silver nanoparticle layers

Abstract

I have fabricated gold and silver nanoparticle layers on amino-terminated glass substrates by immersion processes from aqueous colloidal solutions of gold and silver nanoparticles. The composition ratio of nanoparticles on the modified substrates was varied by the mixing ratio of corresponding colloidal solutions of nanoparticles. Raman signals of rhodamine 6G were observed on the nanoparticle-modified substrates. In the case of the mixed gold and silver nanoparticle-modified substrates, the intensities of the Raman signals were larger than the intensities expected from a simple proportional sum of the Raman signals obtained using a gold nanoparticle layer or a silver nanoparticle layer. The nonlinear enhancement properties of the Raman signal intensities may be attributable to unique localized surface plasmon resonance between the gold and silver nanoparticles. © 2012 The Surface Science Society of Japan.