MnOx-CeOx symbiotic nanozyme with oxygen vacancy-enriched structure for enhanced antibacterial therapy

The development of high-performance nanozymes for antibacterial treatment is critical to addressing global public health challenges. Herein, we report a novel MnOx-CeOx nanozyme with abundant oxygen vacancies (Ovs), synthesized via a H₂ activation strategy, which exhibits exceptional peroxidase-like (POD) activity and broad-spectrum antibacterial efficacy. Uniform CeO₂ nanorods were synthesized using a classic two-step hydrothermal method, followed by the growth of MnOx on the surface via atomic layer deposition. Subsequent H₂ reduction introduced Ovs into the MnOx-CeOx system, significantly enhancing its catalytic performance. Studies reveal that the Ov-rich structure facilitates efficient electron transfer, enabling the nanozyme to catalyze hydrogen peroxide into hydroxyl radicals as the primary reactive oxygen species. The optimized MnOx-CeOx nanozyme demonstrates potent antibacterial activity against both S aureus and E. coli achieving near-complete bacterial eradication under weakly acidic conditions. This work provides a strategic approach for designing high-performance nanozymes via defect engineering, offering promising solutions for antibiotic-free antibacterial therapies.