Stable gold nanoparticles synthesis using but-2-yne-1,4-diol – a simple approach

Abstract

In this work, we report our findings on a new room-temperature method that bridges the features of thermal citrate-reduction and the polyol process. It entails adding water-soluble unsaturated diols to HAuCl₄. Reduction of Au³⁺ by but-2-yne-1,4-diol to Au nanoparticles takes place instantaneously and the nanoparticles are stable even without the use of external surface-active stabilizing agents. Among the other diols (but-2-ene-1,4-diol, butane-1,4-diol), but-2-yne-1,4-diol proves to be an excellent reducing agent. This work demonstrates how the fundamental paradigms of simple multiple bond chemistry can be of use in developing a toolkit for the expeditious synthesis of stable gold nanoparticles of different shapes and sizes from 8 to 140 nm. Incidentally, the reaction sequence also allows ultraviolet-visible (UV-vis) spectroscopic monitoring of the particle formation.