NH₂-MIL-88B@TP-TA@CuS for photothermal catalytic synergistic antibacterial activity

Reactive oxygen species (ROS) provide a promising way to fight bacterial infection and meet the persistent challenge of antibiotic resistance. Nanoenzyme mimics natural enzyme and becomes an effective regulator of ROS level. In this study, NH₂-MIL-88B with high specific surface area was selected as the core, and the covalent organic skeleton material TP-TA COF was wrapped by "sequential growth" technology. Subsequently, through the second hydrothermal treatment, the inorganic material CuS with excellent photothermal performance was integrated into the outer layer, and the NH₂-MIL-88B@TP-TA@CuS_X composite nanoenzyme was synthesized. Different from the traditional nano-enzyme, NH₂-MIL-88B@TP-TA@CuS_X nano-enzyme still has good catalytic effect under neutral conditions (pH=7). In addition, NH₂-MIL-88B@TP-TA@CuS_X has good near infrared (NIR) absorption rate and high photothermal conversion efficiency (PTCE is 48.7 %), which can be used for photothermal treatment (PTT) of bacteria. Mild photothermal effect can further enhance the enzyme-like catalytic activity of NH₂-MIL-88B@TP-TA@CuS_X, so that H₂O₂ can be more efficiently catalyzed to produce a large number of ROS. The experimental results in vitro show that NH₂-MIL-88B@TP-TA@CuS_X can effectively kill Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in the presence of laser irradiation and H₂O₂.