Simulated Enzyme Activity and Efficient Antibacterial Activity of Copper-Doped Single-Atom Nanozymes

Nanozymes with good biocompatibility are novelantibacterial agents becausethey mimic the structure andproperties of enzymes and destroy bacterial structures bygenerating reactive oxygen species in large quantities. Herein, wesynthesized a Cu single-atom nanozyme (Cu-N-C) with intrinsicperoxidase- and oxidase-like activities. Cu-N-C can generatemiddotOHand O2middot-during oxidase-catalyzed reactions, which have goodantibacterial effects. Meanwhile, the antimicrobial performance canbe further enhanced by light emitting diode light incubation due tophotocatalysis. Lethal disruption of the membrane structure wasconfirmed by biofilm staining and scanning electron microscopyanalysis. Notably, the antibacterial effect of Cu-N-C (MIC = 16 mu g/mL) was significantly better than that of vancomycin (MIC = 1500 mu g/mL), a commonly used drug for methicillin-resistantStaphylococcus aureus, and Cu-N-C outperformed the positive control cephalexin and gentamicin in terms of resistance development(27.3% less production of drug-resistant bacteria). Good biocompatibility was also verified using the MTT method, hemolysisanalysis, and routine blood measurements in mice. The results of this work suggest that Cu-N-C has great potential for clinicalapplications as an efficient metal antimicrobial agent.