Reduced Reactivity of Aged Au Nanoparticles in Ligand Exchange Reactions

Solutions of alkanethiol-protected Au nanoparticles undergo a slow aging process over a period of several days, which dramatically reduces their reactivity in a place-exchange reaction with disulfides. This behavior was tentatively attributed to the reorganization of the most reactive binding sites (e.g., defect sites) on the nanoparticle surface.