Photocatalytically Activated Cu‐N 1 S 3 Single‐Atom Nanozyme: Enhancing Enzyme Activities and Antibacterial Synergy for Highly Efficient Fruit Preservation

Abstract Postharvest preservation urgently demands innovative solutions bridging atomic precision with practical scalability. Here, a distinctive photocatalysis‐driven self‐assembly strategy is presented that fundamentally diverged from conventional high‐temperature syntheses by enabling precise single‐atom coordination under ambient conditions. This approach, utilizing α‐lipoic acid (α‐LA) as coordination ligand, achieved the mild assembly of S‐coordinated Cu single‐atom nanozymes (Cu/CNS) while significantly enhancing their enzymatic activity. The resulting material demonstrated unprecedented multi‐enzyme mimetic activities (catalase‐, oxidase‐, and glutathione oxidase‐like) with catalytic efficiency surpassing conventional nanozymes by orders of magnitude. The Cu/CNS exhibits near‐perfect antimicrobial efficacy against Escherichia coli ( E. coli ), Staphylococcus aureus ( S. aureus ), and Botrytis cinerea ( B. cinerea ) through synergistic mechanisms. When integrated into chitosan‐gelatin films (Cu/CNS@CS‐Gel), it forms active packaging with pH‐responsive behavior, exceptional barrier properties, and mechanical strength. Crucially, the synthesis is simple, scalable, and environmentally adaptable. Using strawberries and kiwifruits as representative examples, Cu/CNS@CS‐Gel more than doubled the shelf life while efficiently maintaining nutritional quality. Beyond food packaging, this coordination chemistry platform is generalizable to other metal‐ligand systems, offering a versatile toolbox for sustainable agriculture. By bridging atomic‐level design with practical feasibility, the work advances sustainable nanozyme implementation in food systems.