Plasmon resonance absorption in sulfide-coated gold nanorods

Abstract

Gold nanorods 100 nm in diameter were grown within polycarbonate membranes as templates by the electrodeposition technique. A low-temperature sulfidation process was used to make gold sulfide nanoshells around the nanorods with a thickness of ~7 nm. Optical absorption measurements were carried out on sulfide-coated gold nanorods obtained by dissolving the polycarbonate membrane. Several peaks were observed. These were analyzed on the basis of longitudinal and transverse modes of gold nanorods, the core-shell structure of gold-gold sulfide, and the presence of nanoparticles of gold. Theoretical analysis was carried out using a modified Mie scattering formalism. Satisfactory agreement between experimental results and theoretical fits were obtained.