Photo-Triggered On-Demand Carvacrol Vapor Release From Nano-Generators For Non-Contact Bacterial Inactivation Between Nanomaterials And Bacteria

Foodborne illness outbreaks have significantly impacted public health. The contact antibacterial nanomaterials may have potential migration of nanomaterials and thus bring safety concerns. In this work, we develop phototriggered nano-generators for on-demand release of antibacterial essential oil vapor to achieve a non-contact antibacterial strategy between nanomaterials and target bacteria. This photo-triggered nano-generator (Fe3O4@PDA-COOH@ZIF-67/carvacrol, FPZC) is composed of photothermal Fe3O4@PDA-COOH cores in a zeolitic imidazolate framework-67 (ZIF-67) shell with loaded antibacterial carvacrol. Briefly, these nanogenerators have magnetic transfer and immobilization, photo-thermal conversion, and controlled carvacrol vapor release capacities. Under laser irradiation at wavelength of 808 nm for 60 s, 80 mg FPZC can rapidly release carvacrol vapor to 171.0 mu g/L in the air to completely inactivate Staphylococcus aureus and Escherichia coli at initial amount of 5 log CFU. Photo-triggered nano-generators exhibit flexible carvacrol release property, high photo-triggered killing rate (100%), and good recyclability (5 cycles). Compared to conventional contact antibacterial strategy, nano-generators cannot bring safety concerns with potential nanomaterial migration into sterilized material, and therefore provides promise in practical applications especially in food-related sterilization.