Breaking the durability barrier with d band optimized Cu Fe twin crystal nanozymes for long term suppression of Botrytis cinerea

Nanozymes that emulate the catalytic function of natural enzymes often suffer from self-depletion, limiting their long-term efficacy for practical applications. Here, we report an antifungal nanozyme composed of copper-iron nanocrystals (CuFe NCs) engineered through a Twinned Nanozyme Protection Strategy (TNPS). Leveraging the continuous electron-donating role of Cu²⁺ ions, these CuFe NCs sustain enzymatic activity for over a year, achieving prolonged antifungal effects. Computational chemistry analyses reveal that in the Cu-Fe twinned crystal nanozyme system, the asymmetric four-coordination of Fe atoms shifts the Fe 3 d orbital closer to the Fermi level, facilitating electron transfer from Cu to Fe via oxygen atoms. This mechanism enhances the nanozyme's catalytic activity, ensuring lasting antifungal efficacy. Remarkably, CuFe NCs demonstrate potent antifungal activity by generating endogenous H₂O₂ under oxidative stress within the fungus. Additionally, a multifunctional film (CuFe NCs/sodium alginate/gelatin (Cu-Fe/SL)) is developed, combining water retention with antifungal properties, providing over 19 days of protection for perishable foods and maintaining moisture for more than a week. This antifungal film reduces production costs by 80% compared to conventional antimicrobial films. The durable activity of CuFe NCs offers a promising approach to advancing post-harvest food preservation strategies.