An “all in one” strategy to boost antibacterial phototherapy via porphyrin and boron dipyrromethenes based covalent organic framework

Abstract

Bacterial drug resistant is considered as a major threat to human health. Antibacterial phototherapy (PT) including photodynamic and photothermal therapy has attracted increasing attention owing to spatiotemporal precision, no drug resistance, and low systemic toxicity. However, the efficacy of photodynamic or photothermal therapy alone is limited by low oxygen concentration and high sterilization temperature, respectively. Herein, an “all in one” strategy is proposed and a porphyrin and boron dipyrromethenes (bodipy) based covalent organic framework (COF), named as Tph-BDP-COF, is synthesized to manipulate the excitation energy dissipation pathway, and thus realizing excellent synergetic antibacterial phototherapy. The “all in one” hybrid exhibits a narrow optical bandgap (1.33 eV) and a fast energy and electron transfer compare with porphyrin-base COF-366, hence improving intersystem crossing process and photothermal conversion. Thus, Tph-BDP-COF showed superior ROS generation and excellent photothermal conversion ability, consequently giving an efficient “all in one” antibacterial activities (97 %) compared with the porphyrin-based COF-366 (54 %). These findings give inspiration for the “all in one” phototherapy materials design.