Bacitracin-Functionalized Dextran-MoSe with Peroxidase-like and Near-Infrared Photothermal Activities for Low-Temperature and Synergetic Antibacterial Applications.

Bacitracin (an antimicrobial peptide, AMP)-modified dextran-MoSe nanosheets (AMP/dex-MoSe NSs) were constructed and applied for low-temperature and synergetic antibacterial applications. The near-infrared (NIR) photothermal and peroxidase-like activities of dex-MoSe were combined with the bacterial membrane-binding ability of AMP through electrostatic adsorption, and a multimode antibacterial method was realized. HO was converted into a hydroxyl radical (·OH) by AMP/dex-MoSe, which exhibits a higher antibacterial activity and can avoid the toxicity of a high concentration of HO. Importantly, the production of ·OH and the antibacterial efficiency of AMP/dex-MoSe were accelerated by low-temperature heat sterilization with NIR irradiation. Owing to the AMP-guided binding and destruction effect to the bacterial membrane, AMP/dex-MoSe shows a better antibacterial effect on Gram-negative under NIR irradiation as compared to catalytic treatment or NIR photothermal sterilization alone. Furthermore, the cytotoxicity and hemolysis of AMP/dex-MoSe were weak and in a relatively safe range. This multimode antibacterial strategy based on the AMP/dex-MoSe nanozyme will pave a way for the development of more safe and efficient antibacterial applications.