Mo-doped ZnO NPs with NIR light enhance peroxidase-like nanozymes and trigger photothermal for bacteria eradication

Abstract

Nanozymes can catalyze substrates generating reactive oxygen species (ROS) and serve as broad-spectrum antibacterial materials. In this research, near-infrared (NIR, 808 nm) light-responsive molybdenum (Mo)-doped ZnO nanoparticles (Mo/ZnO NPs) with superior peroxidase (POD)-like activity were synthesized by hydrothermal. Importantly, Mo/ZnO NPs with abundant oxygen vacancies (OV) showed POD-like catalytic activity enhanced by near-infrared (NIR) light, resulting in improved photothermal performance and intracellular ROS levels, which efficiently killed both Gram-negative and Gram-positive bacteria and disrupted bacterial biofilm formation. The minimum bactericidal concentrations (MBCs) of Mo/ZnO NPs against E. coli, AREC, S. aureus, and MRSA were in the range of 5–14 μg mL⁻¹, showing strong antibacterial activity. In addition, the intrinsic antibacterial mechanism indicated that the antibacterial action of Mo/ZnO NPs may involve cell membrane damage, ROS generation, and protein leakage promotion. This research provides a novel antibacterial approach by combining the catalytic production of ROS and NIR photochemical catalysis effects of nanozymes for efficient treatment of bacteria.