Growth of High-Density Gold Nanoparticles on an Indium Tin Oxide Surface Prepared Using a “Touch” Seed-Mediated Growth Technique

This paper reports our novel approach in an attempt to grow high-density gold nanoparticles on an indium tin oxide (ITO) surface using an improved “touch” seeding technique, instead of the “normal” seeding approach, in a seed-mediated growth procedure as we reported previously [Kambayashi et al., Cryst. Growth Des. 2005, 5, 81−84]. The present approach provides a simple and useful strategy to promote the growth of gold nanoparticles on ITO surfaces by simply touching the surface that has already been covered with a drop of gold nanoparticle seed solution with a tissue paper. The FE-SEM characterization of the growth of gold nanoparticles on two different surface structures, i.e., rough and smooth structures, has confirmed that this approach is very effective and prospective in fostering the growth of high-density gold nanoparticles with a relatively small size (ca. 10−30 nm) of spherical-like structure. An optical properties study confirmed that the modified ITO system could be used as a functionalized optically transparent electrode for spectro- and photoelectrochemical applications.