Nanoparticle assemblies and interactions

Abstract

Silica nanoparticles coated with functionalized organosilane molecules are used as substrates for the formation of assemblies of gold nanoparticles. In an assembly of nanoparticles, the optical response of each nanoparticle is affected by scattering from the other nanoparticles in the assembly. Molecularly-linked aggregates of nanoparticles are constructed by immobilizing a layer of gold nanoparticles on the silica nanoparticle surface, specifically adsorbing bifunctional linker molecules to the immobilized gold nanoparticles, and using the second functional group to bind more gold nanoparticles sufficiently close for interactions to occur. A second type of assembly occurs when clusters of small gold nanoparticles spontaneously form and attach to the silica nanoparticles. The dependence of this process on the solvent. and the organosilane coating of the silica nanoparticles is presented and considered with calculations of the potential energy between a pair of nanoparticles.