Fully Triazine-Based Covalent Framework for Antibacterial Phototreatment with High Biosafety

The application of antibacterial photocatalytic therapy remains a great challenge due to the limitations of photocatalytic efficiency and biosafety of photocatalysts. Herein, we report an organic semiconductor catalyst featuring a unique covalent triazine framework (CTF) structure, which is entirely composed of triazine-based rings. This catalyst exhibits the lowest forbidden bandgap, full spectral absorption range, and high biosafety, achieving a record-high antibacterial activity under visible light irradiation. The experimental and theoretical results confirm that the CTF structure broadens the light absorption range of carbon nitride and enhances the separation efficiency of photogenerated electron-hole pairs, which improves the photocatalytic activity. The unique CTF structure not only exhibits excellent antibacterial activity toward both Escherichia coli and Staphylococcus aureus but also eradicates Staphylococcus aureus in a mouse wound infection model and greatly promotes wound healing. The in vivo toxicity evaluation was conducted on the physiological activities of Drosophila, confirming the high biosafety and great potential of as-prepared CTF/poly(vinyl alcohol) hydrogel for antibacterial and wound healing applications.