Doping of Silver Atom Enhances the Fluorescence Intensity in Glutathione Functionalized Gold Nanoclusters

Glutathione (GSH) is a widely used surface ligand for stabilizing metal nanoclusters owing to its biocompatibility, strong metal‐chelating ability, antioxidant properties, and minimal affinity for endogenous cellular proteins. However, the low quantum yield of GSH‐protected gold nanoclusters (GSH‐Au NCs) limits its practical applications. In the present study, silver (Ag) doping is employed in GSH‐Au NCs to significantly enhance the photoluminescence intensity as well as lifetime, while preserving the microenvironment and the surface reactivity essential for subsequent functionalization. The doped nanoclusters exhibit a remarkable sixfold increase in luminescence. This is attributed to the modulation of metal(I)‐thiolate motifs and the amplification of aurophillic interactions, leading to more rigid structure which help to reduce non‐radiative deexcitation pathways.