Comparison of spherical nanogold particles and nanogold plates for the oxidation of dopamine and ascorbic acid

Spherical gold nanoparticles of different size and Au nanoplates were grown at indium tin oxide surface and characterized using SEM. The application of different electrodes in voltammetry for determination of dopamine and ascorbic acid indicated that oxidation of these biomolecules occur at these electrodes in diffusion controlled process and Au nanoplates modified indium, tin oxide electrodes exhibit atleast two to three times higher current than spherical nanogold particles of different size. The observed behaviour suggests that Au nanoplates exhibit higher electrocatalytic activity than spherical gold nanoparticles. The reason for such a behaviour may be due to their (1 1 1) lattice plane as the basal plane as well as due to more available surface edges. As dimensions of nanoplates is of the order of 400-500 nm, the increased surface area in the case of nanoplates also appears to play a significant role. (C) 2009 Elsevier B.V. All rights reserved.