FeCu–P/carbon dots with multi-enzyme activity catalyze reactive oxygen species production for enhanced antibacterial activity

Metal oxides with peroxidase (POD)-like and halogen peroxidase (HPO)-like catalytic activities effectively eliminate bacteria by catalyzing reactive oxygen species (ROS) production, including hydroxyl radicals (·OH) and hypobromous acid (HBrO)/hypochlorous acid (HClO). While metal phosphides generally exhibit higher catalytic activity than metal oxides, bimetallic compounds tend to show better catalytic activity than monometallic compounds. However, there is currently a lack of bimetallic phosphides nanozymes with enhanced POD- and HPO-like activities to selectively produce ·OH and HBrO/HClO for antibacterial applications. Here, FeCu–P/carbon dots (FeCu–P/CDs) nanozymes show multi-enzyme activity to catalyze ROS production for enhanced antibacterial activity. FeCu–P/CDs nanozymes demonstrate POD-like, HPO-like and superoxide dismutase (SOD)-like activities. POD-like activity of FeCu–P/CDs nanozymes with a specific activity of 37.9 U/mg is 8.2 times improved than Cu–P/CDs. FeCu–P/CDs nanozymes show enhanced antibacterial activity by catalyzing the production of ·OH and HBrO/HClO through dual pathways, respectively. Based on the POD-like catalytic pathway, FeCu–P/CDs nanozymes achieved antibacterial rates exceeding 99.9 % against E. coli and S. aureus at 25 μg/mL and 80 μg/mL, respectively, which are significantly higher than those of Cu–P/CDs and Fe–P/CDs. Based on the HPO-like catalytic pathway, FeCu–P/CDs nanozymes demonstrated antibacterial effects against E. coli and S. aureus , achieving an antibacterial rate of 98.7 % against E. coli at 400 μg/mL. This work will inspire the exploration of a variety of bimetallic species-phosphate/carbon nanomaterials with high catalytic activity to enhance antibacterial properties via multi-enzyme activity pathway.