Fenton chemistry activation in metal-organic frameworks for synergistic bacteria eradication

Abstract

The development of novel antibacterial strategies as alternatives to antibiotics is of great significance but remains considerable challenges due to the lack of safe, effective, and broad-spectrum agents. Here, we explored the potential of a biocompatible metal–organic framework Fe-MIL-53-NH2 (FM) for reactive oxygen species (ROS)-based antibacterial applications. However, FM was found to be catalytically inert due to the very weak reducibility of Fe3+ toward H2O2. To address this challenge, we incorporated a small amount of Co2+ (0.98 %) into FM (CFM), successfully activating Fenton chemistry and achieving a notable 5.5-fold improvement in Fenton activity. Density functional theory (DFT) calculations revealed that a very small amount of Co2+ doping significantly reduces the energy barrier of the Fenton reaction by shifting the d-band center to the Fermi level and optimizing the charge density of active Co atoms. We further enhanced the antibacterial properties of CFM by modifying it with the photothermal agent polydopamine (PDA), resulting in CFMP. Through the synergistic effects of ROS and photothermal properties, CFMP exhibited remarkable antibacterial activity, with bacterial eradication rates exceeding 99 % against both E. coli and S. aureus. Moreover, in vivo experiments demonstrated the exceptional efficacy of CFMP in sterilizing S. aureus-infected wounds, while causing negligible damage to other major organs. This study not only highlights the role of atom engineering in activating Fenton reaction, but also provides rational designs for a synergistic antibacterial strategy via powerful MOFs chemistry.