Efficient Bacteria Killing by Cu₂WS₄ Nanocrystals with Enzyme-like Properties and Bacteria-Binding Ability

Antibacterial agents with high antibacterial efficiency and bacteria-binding capability are highly desirable. Herein, we describe the successful preparation of Cu₂WS₄ nanocrystals (CWS NCs) with excellent antibacterial activity. CWS NCs with small size (∼20 nm) achieve more than 5 log (>99.999%) inactivation efficiency of both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) at low concentration (<2 μg mL^-1) with or without ambient light, which is much better than most of the reported antibacterial nanomaterials (including Ag, TiO₂, etc.) and even better than the widely used antibiotics (vancomycin and daptomycin). Antibacterial mechanism study showed that CWS NCs have both enzyme-like (oxidase and peroxidase) properties and selective bacteria-binding ability, which greatly facilitate the production of reactive oxygen species to kill bacteria. Animal experiments further indicated that CWS NCs can effectively treat wounds infected with methicillin-resistant Staphylococcus aureus (MRSA). This work demonstrates that CWS NCs have the potential as effective antibacterial nanozymes for the treatment of bacterial infection.