Copper-doped melanin nanozyme with enhanced photothermal and peroxidase-like catalytic property for synergistic antimicrobial effect

Natural enzymes composed of protein and metal cofactor have great catalytic activity. Here, melanin was bound with Cu2+ (M-Cu) as nanozyme to mimic native enzyme function. The results showed that the coordination of Cu2+ significantly enhanced the near infrared light absorption and photothermal performance (PTT) of melanin. M-Cu displayed outstanding peroxidase (POD)-like catalytic activity that converting H2O2 into toxic hydroxyl radicals (.OH). The combination of POD nanozyme catalysis and enhanced photothermal property could exert synergistic antibacterial effect to effectively kill bacteria within only 5 min under 808 nm laser irradiation, which may provide a broad perspective for the design of antimicrobial materials.

Automated summary

By binding Cu2+ with melanin to form a nanozyme, the near infrared light absorption and photothermal performance of melanin were significantly enhanced. The nanozyme exhibited excellent peroxidase-like catalytic activity, converting H2O2 into toxic hydroxyl radicals. The synergistic antibacterial effect achieved through the combination of nanozyme catalysis and enhanced photothermal property could effectively kill bacteria within only 5 minutes under 808 nm laser irradiation, which holds great potential for the design of antimicrobial materials.