Synthesis and Characterization of Silver-Plated Gold Nanostars for Biomedical and Sensing Applications

Abstract

The physiochemical and optical characteristics of nanoscale colloids rely on their chemical composition, shape, and size. Gold nanostars are anisotropic multibranched nanoparticles with a central core and several sharp delicate tips, command significant attention in nanodiagnostic, imaging and sensing applications. Anisotropic nanoparticle’s shape, size and tips are of a great importance dominating their properties and performance in biomedical applications and sensing strategies which require optimization. Several factors can affect these features. In this regard, silver seed mediated goldnanostars were synthesized and characterized using different characterization techniques. Furthermore, the effect of the gold solution concentration on the morphology of the synthesized gold nanostars was investigated. Result indicated successful synthesis of gold nanostars with high yield and multiple sharp branches. EDX line scanning profile of the gold nanostars showed that there is a thin coating of silver in the shell of the nanostructures. Moreover, further analysis of TEM images of AuNSs in atomic scale resolution demonstrated that there are no dislocations and defects in the structure of the synthesized gold nanostars. Positive zeta potential of 42.3 mV confirmed good stability against aggregation in terms of charge stabilization. Synthesized anisotropic gold nanostars with near-infrared surface plasmon resonance in which tissue absorption and autofluorescence are minimized, can be used for multiple purposes on the biomedical field and sensing assays.