Multienzyme-Mimicking Cu2O/AuPt with Efficient Photothermal Effects for Superior and Long-Term Antibacterial Performance

Microbial evolution, combined with antibiotic overuse, has accelerated the emergence of antibiotic-resistant bacteria. These bacteria pose significant risks to human health and the ecological environment. To address this challenge, researchers are increasingly focusing on multifunctional nanostructures with multiple antimicrobial mechanisms. Herein, Cu2O/AuPt3 was rapidly generated by the in situ reduction of Au3+ and Pt4+ on the surface of Cu2O NPs. The decorated AuPt NPs confer Cu2O/AuPt3 with a high photothermal conversion efficiency of ∼56.89% within 200 s and endow the obtained material with multienzyme-mimicking activity, including peroxidase (POD)-, oxidase (OXD)-, and glutathione oxidase (GSHOx)-like activities. Cu2O/AuPt3 nanoparticles showed low toxicity toward L929 cells when the concentration was below 40 μg·mL–1. In vitro antibacterial tests demonstrated that the synergistic antibacterial mechanism resulted in effective and long-lasting antibacterial properties against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Cu2O/AuPt3 exhibited superior rapid bactericidal capability compared to vancomycin (VAN), and it retained good bactericidal activity even in 40% human serum. Furthermore, Cu2O/AuPt3 could keep silk fibroin free from S. aureus contamination for at least one month at a concentration of 40 μg·mL–1. This study provides useful information for further research on composite materials with multienzyme-mimicking activity.