A novel Fe3O4/CuOx nanozyme: Intrinsic peroxidase-like activity to kill bacteria and sterilize wounds

Herein, we report a Fe3O4/CuOx composite with intrinsic highly peroxidase-like activity. The Fe3O4/CuOx composite maintained high activity in the normal skin pH range (4.0-6.0) and over a wide temperature range (25-60 degrees C). The prepared Fe3O4/CuOx exhibited good bactericidal properties against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) at low H2O2 concentration (100 mu M). The composite could also effectively destroy the biological film and prevent the emergence of new bacterial film. In addition, Fe3O4/CuOx was easily separated from the media by external magnets and reused five times while maintaining high antibacterial activity. The predominant free radicals (center dot OH and 1O2) were identified during the sterilization process using a trapping experiment and electron spin resonance (ESR). In addition, the dressing of Fe3O4/CuOx was designed to accelerate skin wound healing, maintaining good cytocompatibility significantly. This composite Fe3O4/CuOx is promising for a wide range of uses in bacterial management.