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.