H2O2 self-supplying Mo/Fe@CuO2 nanozyme with NIR light enhanced catalytic activity and photothermal synergistic antibacterial application

Nanozymes have drawn increasing attention due to unique enzyme-mimic catalytic activities for the treatment of bacterial infections. Herein, a novel tri-metal nanozyme for synergistic eradication of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was generated by Mo/Fe doped carbon dots (Mo/Fe-CDs) wrapping copper peroxide (CuO2) nanozyme (Mo/Fe@CuO2). Mo/Fe@CuO2 showed near-infrared (NIR) light-enhanced peroxidase-like catalytic activity, and H2O2 self-supply to promote the generation of reactive oxygen species (ROS) for highly efficient antibacterial photothermal therapy. The CuO2 could generate H2O2 in the acidic microenvironment, and Mo/Fe-CDs consequently could convert H2O2 to hydroxyl radicals (& sdot;OH), resulting in the improvement of sterilization efficiency. Interestingly, Mo/Fe-CDs could activate the transformation of Cu2+ to Cu+ through the co-catalytic reaction based on the Mo4+/Mo6+ and Fe3+/Fe2+ redox couples, and provided photonic hyperthermia (PTT) to enhance the peroxidase-like activity. Meanwhile, Mo/Fe@CuO2 showed glutathione (GSH) oxidase-like activity, which can achieve the depletion of glutathione (GSH) in bacteria, thus significantly improving the bactericidal effect. The collaborative eradication of bacteria, through innovative metal carbon-based nanozyme technology, provides a powerful and feasible approach to treating bacterial infections that threaten human health.