Magnetic bio-based Fe3O4@urushiol-Fe polymeric nanoparticles for efficient photothermal sterilization

Many advantages of photothermal sterilization make it very promising in the field of sterilization. Biomass micro-nanoparticles with photothermal properties are considered worthy of development as photothermal sterilization materials. Urushiol, the main component of natural sap from lacquer tree, was applied to react with green-vitriol by the adjusted the concentrations of ferrous ion through the chemical synthesis method to prepare a novel magnetic composite nanoparticle with Fe3O4as the central core wrapped by urushiol-Fe chelate polymer. Under 808 nm near-infrared irradiation (0.12 W cm−2), the Fe3O4@urushiol-Fe polymeric nanoparticles were rapidly heated up to a maximum temperature of 104.9 ℃, implying good photothermal conversion performance. The nanoparticles were applied for the effective inactivation of bacteria such as Escherichia coli and Staphylococcus aureus. The optimal dose and irradiation power for sterilization were 0.5 mg and 1 W cm−2, respectively. The composite nanoparticles exhibited good photothermal conversion stability even after multiple photothermal heating and photothermal sterilization. The biomass magnetic composite Fe3O4@urushiol-Fe polymer nanoparticles had the advantages of simple preparation, high efficiency of photothermal conversion, significant sterilization effect, and easy collection, which demonstrated a broad application prospect in the field of photothermal sterilization.