A simple shape-controlled synthesis of gold nanoparticles using nonionic surfactants

Abstract

Green and simple synthesis strategies have gained tremendous popularity for the production of anisotropically-shaped noble metallic nanoparticles. The long-term stability of the produced particles, the short timescale of the target reaction(s), as well as the use of non-toxic chemicals, are pivotal features of a useful green procedure. Herein we describe a simple and convenient wet-chemical approach to synthesize stable, non-toxic and water-soluble small gold nanotriangles (GNTs) and gold nanospheres (GNSs) in one step at room temperature, using Tween 20 and Tween 80, respectively. A high level of purity and monodispersity was obtained for the GNTs, in addition to an excellent colloidal stability of both GNTs and GNSs in media exhibiting a high ionic strength and over a wide pH range. The presented strategy, which exploits the dual functional properties of Tween as a co-reducing and stabilizing agent, eliminates the presence of hazardous chemicals such as toxic surfactants, hazardous organic solvents and harsh reducing agents during the synthesis process, and hence could pave the way for the facile usage of the spherical and triangular gold nanoparticles for clinical or biological applications. The resulted particles were characterized by UV-Vis spectroscopy, dynamic light scattering and transmission electron microscopy.