Tuning the Size of Gold Nanoparticles with Repetitive Oxidation-reduction Cycles (original) (raw)

A simple method to control the size of gold nanoparticles (AuNP) using repetitive oxidation-reduction cycles is described. First, AuNP are shown to be readily immobilized onto an indium-doped tin oxide coated glass surface using cyclic voltammetry nanoparticle containing citrate buffer. Subsequently, the attached AuNPsize can be reduced to a desired level by potential cyclingin the range from 0 V to +1.1 V (vs. Ag/AgCl).Gradual AuNPdiameter decrease was attributed to the formation of gold oxide upon anodic potential sweep and the partial solubilization of the Au(III) species during subsequent reduction of gold oxide in the absence of gold chelator (e.g.,Cl -, Br -, or CN -) normally necessary for anodic gold dissolution.