Fe-doped mesoporous carbon nanospheres for synergistic photothermal-chemodynamic antibacterial therapy

Multidrug-resistant bacterial infections have become a critical public health crisis, urgently calling for antibiotic-independent antimicrobial strategies. Herein, we successfully construct a multifunctional nanoplatform based on Fe-doped mesoporous carbon nanospheres (MCNs-Fe_x) via a template-assisted coordination-pyrolysis strategy. By systematically varying the Fe doping level, we elucidate the regulatory effects of Fe incorporation on nanosphere morphology, mesoporous architecture, defect density, and surface chemical states, and identify 10 mg FeCl₃ doping as the optimal proportion (MCNs-Fe₁₀). MCNs-Fe₁₀ exhibits both high photothermal conversion efficiency (40.34%) and excellent peroxidase-like activity following Michaelis-Menten kinetics, maintaining robust stability under infected acute wound-mimicking acidic conditions (pH 5.5). In vitro antibacterial assays confirm that MCNs-Fe₁₀ achieves efficient eradication of both Escherichia coli and Staphylococcus aureus through the synergistic photothermal therapy and chemodynamic therapy (CDT), markedly surpassing that of monotherapy alone. Mechanistically, the photothermal effect not only directly damages bacterial membranes but also accelerates Fenton reaction kinetics and promotes reactive oxygen species transmembrane permeation, thereby amplifying the CDT efficacy. Furthermore, cytotoxicity assessments confirm good biocompatibility. This work establishes a structure-guided design for carbon-based nanozymes and provides a safe, efficient platform for offering a non-antibiotic strategy to mitigate the risk of drug resistance.