Byproduct-induced in-situ formation of gold colloidal superparticles

Current work presents a simple and efficient method for the preparation of gold superparticles. The self-assembly of gold nanoparticles into colloidal superparticles was realized in-situ during the preparation of nanoparticles when a type of thiol molecules were used as ligands. Further investigation reveals that t-butylamine hydrochloride, an ionic byproduct generated during the redox reaction of precursors, plays a key role in the formation of gold superparticles. The polarity of monolayers made from these ligands on the nanoparticle surface allows the interaction of nanoparticles and the ionic byproduct, which is indispensable for the superparticle formation.