Objective To explore the synergistic antibacterial performance of photothermal and enzymatic catalysis mediated by Pd/ZIF-8 nanozyme, and assess its potential for biomedical applications.

Methods The Pd/ZIF-8 nanozyme was prepared by the hydrothermal method, and its structure was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The photothermal conversion performance of the Pd/ZIF-8 nanozyme and its ability to mimic the activities of peroxidase (POD) and glutathione peroxidase (GPx) were evaluated. The cell counting kit-8 (CCK-8) method was used to detect the toxicity of Pd/ZIF-8 to human dermal fibroblasts (HDF-a), and the erythrocyte hemolysis test was used to detect its blood compatibility. The antibacterial performance of Pd/ZIF-8 against Gram-negative bacteria (Escherichia coli, E. coli) and Gram-positive bacteria (methicillin-resistant Staphylococcus aureus, MRSA) under the irradiation of 808 nm near-infrared light was detected.

Results TEM and XRD analyses confirmed the successful synthesis of the Pd/ZIF-8 nanozyme. The Pd/ZIF-8 nanozyme exhibited good photothermal performance with a photothermal conversion rate of 65.3% and good stability. Meanwhile, the Pd/ZIF-8 nanozyme exhibited excellent dual enzyme-like activities (POD and GPx). The results of cytotoxicity and hemolysis tests indicated that Pd/ZIF-8 had good biocompatibility. Under near infrared light irradiation, the antibacterial rates of Pd/ZIF-8 against E. coli and MRSA were 97.3% and 99.41%, respectively (P < 0.0001).

Conclusion The Pd/ZIF-8 nanozyme has the ability to mediate photothermal and enzymatic promotion to achieve synergistic antimicrobial properties. This nanomaterial shows promising application prospects in the field of anti-infection treatment and provides important ideas for the development of new antibacterial agents.