Construction of antibacterial-enhanced 2D ZnO@ZIF-8 nanocomposites based on synergistic antimicrobial mechanisms and application in maize long-term storage.

Abstract

The prevention of bacterial growth and mold during the long-term storage of maize is a long-standing concern. This study introduced a synergistic antibacterial enhanced ZnO nanocomposite prepared by a top-down template method based on self-assembly mechanism. The results showed that 2D ZnO@ZIF-8 nanocomposites, with uniform ZnO encapsulation in dodecahedral ZIF-8 frameworks, exhibiting high surface area and microporous structure. The nanocomposites demonstrated synergistic antibacterial effects through sheet morphology, multi-site activity, and ROS generation, the inhibition rates against Staphylococcus aureus, Escherichia coli, Aspergillus flavus, Aspergillus niger, and Penicillium citrinum were increased by 20.65 %, 38.87 %, 39.91 %, 38.55 %, and 40.34 %, respectively, compared with ZnO. During 42-day simulation storage, it reduced maize surface microbes by 99.5 %, while maintaining safe Zn2+ levels. The treatment suppressed toxigenic fungi, Fusarium, Meyerozyma, Penicillium, and effectively controlled A. flavus without altering species richness. This work presented an ideal ZnO-based antibacterial nanomaterial for long-term safe storage of maize.