Lysine-Engineered Seawater-Tolerant Nanozyme for Sustainable Inactivation of Drug-Resistant Bacteria in Marine Environments

The marine environment has become a critical reservoir for antibiotic resistance genes, driven largely by antibiotic overuse in aquaculture and the global dissemination of pathogens via ocean currents. While nanozymes offer a promising alternative to conventional antibiotics, their practical deployment in seawater remains fundamentally limited by activity loss under alkaline pH and high salinity. To address this environmental compatibility challenge, we developed a seawater-tolerant nanozyme (VOCN@lys) through lysine functionalization of a MOF-derived vanadium oxide. VOCN@lys operates effectively across a broad pH range (2-10) and under high-salinity conditions by maintaining robust dual enzyme-mimicking (oxidase- and peroxidase-like) activities. Notably, VOCN@lys exhibits potent antibacterial activity against methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) through its intrinsic nanozyme catalysis, enabling complete bacterial eradication without the need for exogenous H₂O₂. This work provides an environmentally compatible nanozyme strategy that directly addresses the core limitations of conventional nanomaterials in marine settings, offering a practical approach to mitigate the spread of antimicrobial resistance in aquatic ecosystems.