Overlook of Gold Nanoparticles and Other Metal Nanoparticles Containing Gold

Abstract

Gold nanoparticles have been widely used as a good inorganic red pigment which show dark wine red color. Gold nanoparticles are considered as a long life pigment. Red stained glasses often used in old churches are old glasses containing gold nanoparticles. They are very clear and show dark red color. The history of the chemistry of gold nanoparticles is very long, and began in 1857. Faraday firstly reported the preparation of red gold hydrosol^{1, 2)}. Gold itself is a highly precious materials and show brilliant gold luster. However, gold nanoparticles show considerably different color. Gold has attracted much interest not only from scientists. Such gold nanoparticles can be prepared quite readily by chemical reduction of the corresponding salts, which also support their intensive scientific studies. Recently, Brust et al. reported the preparation of single nanometer-sized gold nanoparticles by NaBH₄ reduction³⁾. This pioneering report introduced explosive expansion of nanoparticle researches. Gold nanoclusters and gold nanocatalysts which are also invented quite recently still continue to attract the peoples’ interest. In this section, I would like to overlook the studies of gold nanoparticles.