One-step synthesis of cystine-coated gold nanoparticles in aqueous solution

A simple method for one-step synthesis of cystine-capped gold nanoparticles (GNPs, >50 nm) in aqueous solution at room temperature has been developed. The size of gold nanoparticles is controllable just by adjusting the pH value of the solution. Importantly, the obtained gold nanoparticles exhibited a better dispersibility in aqueous solution. Such GNPs surface might provide a diversification of available nanoparticulate materials and potential applications in medicine and nanobiotechnology. The reported method will be easy to expand to produce the other nanoparticles modified with cystine. (C) 2007 Elsevier B.V. All rights reserved.