Dynamic study on the transformation process of gold nanoclusters

Abstract

In this paper, the transformation process from Au-8 to Au-25 nanoclusters (NCs) is investigated with steady state fluorescence spectroscopy and time-resolved fluorescence spectroscopy at various reaction temperatures and solvent diffusivities. Results demonstrate that Au-8 NCs, protected by bovine serum albumin, transform into Au-25 NCs under controlled pH values through an endothermic reaction with the activation energy of 74 kJ mol(-1). Meanwhile, the characteristic s-shaped curves describing the formation of Au-25 NCs suggest this process involves a diffusion controlled growth mechanism.