A One-Stone-Two-Birds Strategy to Develop P-Por COF/PDES Composite Gels for Photothermal/Photodynamic Antibacterial Activity and Wearable Strain Sensing.

Flexible wearable electronics face growing bacterial infection risks from prolonged skin contact, creating an urgent demand for flexible materials integrating efficient sensing and antibacterial functions. Herein, a novel phosphorus-containing porphyrin covalent organic framework (P-Por COF) was synthesized via a solvothermal Schiff-base reaction, and incorporated into a polymerizable deep eutectic solvent to fabricate P-Por COF/PDES composite gels through in-situ UV polymerization. The resulting gel exhibited enhanced photothermal performance, improved mechanical properties, and excellent near-infrared (NIR) triggered antibacterial activity. Under 730 nm NIR light irradiation, the P-Por COF/PDES composite gel could reach 76 °C with 4 min, while showing excellent stability of photothermal cycle. Based on the synergistic effect of photodynamic production of singlet oxygen and photothermal effect, the P-Por COF/PDES composite gel resulted in a high bactericidal rate of nearly 100% against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The P-Por COF/PDES composite gel delivered a fracture strain up to 2435.82% and 2.6-fold higher toughness than pure PDES, along with stable, sensitive and self-healable strain sensing for human motion monitoring. Overall, this work provides a simple and effective strategy for developing antibacterial materials and multifunctional gels with integrated therapeutic and sensing capabilities.