A Novel Strategy for Synthesis of Gold Nanoparticle Self Assemblies

Gold nanoparticle self assemblies are one-dimensional structures of gold nanoparticles. Gold nanoparticle self assemblies exhibit unique physical properties and find applications in the development of biosensors. Methodologies currently available for lab-scale and commercial synthesis of gold nanoparticle self assemblies are complex. These methods are often multistep involving linker nanoparticle conjugation steps and external stimuli treatment steps. Here, we present a simple method for synthesis of gold nanoparticle self assemblies. The method involves surfactant-free synthesis of gold nanoparticles, washing of gold nanoparticles with distilled water and irradiation of gold nanoparticles with glow discharge plasma. Thus synthesized gold nanoparticle self assemblies were characterized using electron microscopy and ultraviolet and visible light spectroscopy. Results show that washing with distilled water and irradiation with glow discharge plasma induces assembling of gold nanoparticles into multimers, chain-like structures and networks. Our synthesis method is unique in that it provides full control on the extent of self assembly and at the same time is simple and economical. Our synthesis method facilitates lab-scale and commercial synthesis of gold nanoparticle self assemblies, which, in turn, will promote the application of self assembled gold nanoparticles in the development of novel biosensors, drug-delivery platforms, lab-on-a-chip platforms and a variety of other nano-scale medical device