Assembling gold nanoparticles as nanostructured films using an electrophoretic approach

A three-dimensional array of gold nanoparticles has been assembled on a nanostructured TiO2 template by subjecting the colloidal gold suspension to a dc electric field (50-500 V). By controlling the concentration of gold colloids in toluene and the applied voltage, it is possible to control the thickness of nanostructured gold film without inducing aggregation effects. As indicated by Atomic Force Microscopy, these gold films are highly porous and consist of nanoparticle assembly of fairly uniform size. The surface plasmon characteristics observed in these nanostructured gold films suggest that these particles retain the identity of individual nanoparticles.