Synthesis and size control of gold nanoparticles in regular system of amphiphilic molecules

Abstract

Two synthetic techniques for colloidal gold particles was improved by using SDS. And colloidal Au particles of mean diameters between 5 and 14 nm are synthesized, that exhibit improved monodispersity relative to previously published methods. According to the particular molecular structure of surfactants and different electrons distribution arising from colloidal small sizes and high surface/ volume ratios, it is found that there are a complex between SDS and Au³⁺ (and Au atoms ) during synthesizing colloidal gold nanoparticles and as a stablizer for Au particles, SDS can prevent their further growth. So the colloidal gold particles is monodispersize and more steady. But other surfactants don't affect the process of synthesizing gold nanoparticles because of their structures and properties different from SDS. Gold nanoparticles have considerable bioaffinity and can be applied to study the adsorption of proteins or polypeptides.