In situ Synthesis\nof Zeolitic Imidazolate Framework-11@ZnO\nHeterostructures for Enhanced Antimicrobial Activity and Biological\nPreservation

Storage and transportation are critical processes that\nsignificantly\naffect food quality, with bacterial proliferation serving as a major\ncontributor to deterioration. Preservative films are commonly used\nin food transportation and preservation. However, the approval process\nfor contact-type preservative films remains challenging due to inconclusive\ntoxicity assessments. In this work, we synthesized antimicrobial zeolitic\nimidazolate frameworks (ZIFs) with ZnO microtube heterostructures\n(ZZHs) for contactless biological preservation using the optical vapor\nphase supersaturated precipitation (OVSP) method, combined with an\nin situ solvothermal approach. This ZZH exhibited excellent antimicrobial\nactivity and achieved efficiencies of 90.47% and 98.24% against E. coli and S. aureus, respectively. We also developed a highly flexible ZZH/PDMS film\nthat demonstrated exceptional structural stability under various temperature,\nacid, and alkali conditions, which supported the potential for stable\nintrinsic antimicrobial activity. The hydrophilic nature and high\nspecific surface area of the ZZH/PDMS film were beneficial to capture\nthe dispersed water vapor, bacteria, and other harmful substances,\nwhich enhanced the efficiency of the antimicrobial functional sites.\nThis strategy indirectly inhibited bacterial proliferation by controlling\nambient humidity, thus avoiding direct contact between the film and\nthe fruit. This process was defined as a contactless mechanism. This\nwork offers an avenue for the development of highly flexible and durable\nantimicrobial heterostructure agents for contactless biological preservation\nin future applications.