Emission enhancement and self-healing of a hybrid hydrogel employing Au nanoclusters as cross-linkers

Abstract Au nanoclusters (AuNCs) as a novel type of luminescent nanomaterial have been extensively explored due to low toxicity, excellent photostability and ultrafine size. However, few progresses have been made in producing ultrabright, homogeneous, functional, water-soluble AuNCs. In this regard, we propose an outstanding cross-linker acrylamide modified GSH@AuNCs (AM-GSH@AuNCs) based on a simple one-step pretreatment, achieving a high quantum yield and self-healing hydrogels by copolymerizing with acrylamide. The plentiful network structure of the hydrogel effectively restricts the vibration of the ligands on the AuNCs surface, resulting in a 4-fold enhancement of quantum yield (from 5.6% to 22.8%). Meanwhile, the prepared PAM-GSH@AuNCs hydrogel exhibits self-healing capability and excellent elasticity. It is worth noting that AuNCs are used as cross-linkers in the polymerization reaction for the first time, which supplies a platform to realize the functionalization of gold nanoclusters.