Dual-single-atom nanozyme with stage-adaptive catalytic regulation for infected diabetic wound healing

Infected diabetic wounds remain difficult to treat because persistent bacterial reservoirs coexist with a failure to transition from antibacterial defense to regenerative repair. Here, we report a dual-single-atom nanozyme (FeCo-CN) in which atomically dispersed Fe and Co centers are anchored within a nitrogen-coordinated carbon framework, enabling stage-adaptive regulation of the wound microenvironment. During the early infection phase, FeCo-CN exhibits photothermal-enhanced peroxidase-like activity that efficiently reduces extracellular bacteria and promotes macrophage-mediated intracellular bacterial clearance. As the bacterial burden decreases, the material shows superoxide dismutase- and catalase-like activities that alleviate oxidative stress, preserve mitochondrial function, and favor the shift toward reparative immune responses. These coordinated effects support angiogenesis and tissue regeneration. Overall, this work highlights a dual-single-atom nanozyme strategy that integrates infection control with immune transition and tissue repair in infected diabetic wounds.