Near-Infrared Light-Triggered Bacterial Eradication by Different Morphologies of NH2-MIL-101(Fe)@Ag

Antibiotic overuse has led to drug-resistant bacteria and superbugs, necessitating urgent strategies. MOFs, although they are potential antimicrobial carriers, have limitations at low doses and in single therapy. Here, by adding different amounts of CTAB in the precursor solution, two different morphologies of NH2-MIL-101(Fe)@Ag nanoagents were obtained, namely, NH2-MIL-101(Fe)@Ag-1 (Cube) and NH2-MIL-101(Fe)@Ag-2 (Octahedron). Antibacterial experiments showed that these two nano reagents with both photothermal and photodynamic effects exhibited nearly 100% bactericidal rate against high concentrations of Staphylococcus aureus and Escherichia coli (107 CFU/mL) within 15 min. The combination of inactivation of intracellular proteins and disruption of cell membranes induced by Ag ions and high temperature resulted in NH2-MIL-101(Fe)@Ag 100% in an octahedron showing durable and superior bactericidal performance at low doses (64 μg/mL), which is much better than other antibacterial reagents. Furthermore, the enhanced mechanism was discussed in detail by DFT calculations. A special electron transfer process occurred between Ag and NH2-MIL-101 (Fe) under 880 nm NIR irradiation, which promoted the generation of ROS and enhanced the antibacterial effect. In addition, these two nano reagents have good therapeutic effects on wound healing in vivo due to silver ions and photothermal effects.