CuFe₂O₄/lignin-based carbon composited photothermal and photodynamic agents for synergetic antibacterial therapy

Bacterial infection has become the second leading cause of death in the world. Exploring a new highly antibacterial catalyst to replace traditional antibacterial agent is crucial for the society development of human beings. In this study, CuFe₂O₄/Lg-based carbon composited catalysts were rationally constructed by facile hydrothermal method. Lignin-derived carbon with enormous oxygen-containing functional group was beneficial to anchor CuFe₂O₄ nanoparticles. The close contact interface between CuFe₂O₄ and Lignin-based carbon material was expected to extend the range of optical absorption and promote the separation and transportation of photogenerated carriers. Under NIR (980 nm, 1.5 W/cm²) light irradiation, the as-prepared CuFe₂O₄/Lg (20 μg/mL) exhibited excellent photo/photothermal synergetic in vitro (against Escherichia coli and Staphylococcus aureus) and in vivo (against Staphylococcus aureus-infected mouse wound model) antibacterial performance. Furthermore, the cell count assay kit 8 (CCK-8 kit) demonstrated the good biocompatibility of this material. On the basis of the experimental results, a possible antibacterial mechanism based on the synergetic photothermal and photodynamic therapies was proposed. This work presented a lignin- derived carbon-based highly efficient antibacterial disinfection agent with desirable biosafety.