Ir(IV) and Ir(III) in situ transition promotes ROS generation for eradicating multidrug-resistant bacterial infection.

Whether reactive oxygen species are a consequence or a cause of antibacterial activity is not fully known. A glutathione (GSH)-mediated oxidative defense mechanism is an important factor against bacterial infection. Reactive oxygen species (ROS) storm-mediated bacterial death by depleting GSH is also considered an effective strategy. Therefore, we designed and synthesized hybrid iridium ruthenium oxide nanozymes (IrRuO x NPs), where IrRuO x NPs alternately consume GSH through double redox electron pair auto-valent cycles, while an IrRuO x NP-mediated Fenton-like reaction occurs to realize an ROS storm, which in turn mediates lipid peroxidation to promote bacterial death. The results showed that IrRuO x NPs can effectively inhibit and kill Gram-positive and Gram-negative bacteria in vitro , and can be used as broad-spectrum antibiotics. Importantly, the wound and sepsis models of MRSA infection confirmed the efficient antibacterial activity of IrRuO x NPs in vivo . Accordingly, this study provides a new idea for metal oxide hybrid nanoenzymes and their biological functions.