Functional Evolution of Gold Nanoclusters under Light‐Induction: From Fluorescence to Multi‐Enzyme Mimetic Transition

Abstract Gold nanoclusters (AuNCs) exhibit unique physicochemical properties but their functional transitions under external stimuli remain underexplored. This study reveals that ultraviolet (UV) irradiation triggers structural evolution in AuNCs, causing fluorescence loss while activating dual enzyme‐mimetic activities. UV‐induced particle enlargement and surface restructuring endow AuNCs with peroxidase‐like (POD‐like) and laccase‐like functionalities. The POD‐like activity enables sensitive glucose detection in human serum, while the laccase‐like capability facilitates simultaneous detection and degradation of phenolic pollutants in wastewater. These light‐responsive transformations demonstrate AuNCs' dynamic adaptability, bridging their intrinsic fluorescence and catalytic properties. The findings elucidate photo‐regulation mechanisms in nanomaterial functionality, proposing a novel strategy for designing multifunctional nanosystems applicable in biosensing and environmental remediation. This work advances the development of adaptive nanomaterials with programmable features for biomedical and ecological applications.