The Synthesis and Characterization of Gold Nanoparticles Prepared with Novel Thioether-Ionic Liquids

Gold nanoparticles have found a broad range of applications in the biomedical field including in drug delivery and biosensor development.The latter applications take advantage of a unique optical property called surface plasmon resonance. Easily accessible “bottom-up” synthesis methods are commonly used for the preparation of metal nanoparticles, in which a metal precursor is reduced in the presence of a stabilizing agent to prevent aggregation. Ionic liquids have been used in “bottom up” metal nanoparticle syntheses as stabilizing agents and as a means to functionalize metal nanoparticles’ surface. Due to the strength of gold-sulfur interactions, thiol-stabilized gold nanostructures are of great interest. This project focused on the development of gold nanoparticle syntheses with a series of novel thioether-functionalized ionic liquids. The effect of ionic liquid structure and composition, ionic liquid concentration, and ionic liquid solubility on the synthetic reproducibility, elemental composition, and size of the gold nanoparticles were evaluated. The gold nanostructures were characterized by UV-visible spectroscopy, atomic force microscopy, and scanning electron microscopy with electron dispersive x-ray spectroscopy. Possible interactions between the ionic liquid and HAuCl4 in aqueous solution were studied using fast scan cyclic voltammetry and UV-visible spectroscopy