Surface plasmon resonance of gold nanoparticles aggregated in 2-dimensions

Abstract

Gold (Au) nanoparticles have attracted considerable attention in the fields of nanophotonics and biomolecular sensing due to their strong surface plasmon resonance.An aggregation of Au nanoparticles in colloidal suspensions is one of the motivations for biomolecular recognition such as DNA because their absorption band can be effectively modulated by aggregation. Regardless of the various techniques for preparing particulate monolayers from colloidal suspensions, the aggregation of Au nanoparticles in 2-dimensions for example on a substrate will be a new approach for the fundamental research related to modulation of the surface plasmon band and biomolecular recognition or catalyst application. Also, tunable aggregation of Au nanoparticles in 2-dimensions can be helpful for a wavequide and a template for surface-enhanced Raman spectroscopy. In this study, the aggregations of Au nanoparticles on a substrate, which were prepared by co-sputtering with SiO2 and evaporating in a very short time, were accomplished by simple chemical treatments and red-shift of their absorbance bands were discussed relating with the distribution of Au nanoparticles.