Enhanced antimicrobial performance of D-A covalent organic framework with pyridinium and quaternary ammonium groups and ROS activity

s Bacterial infections pose a threat to human health worldwide. Developing antibiotic-free strategies or integrating multiple bactericidal methods is urgently needed for efficient sterilization. Covalent organic frameworks (COFs) have attracted considerable attentions for killing bacteria using photodynamic and photothermal therapy methods, which prevent drug resistance. In this study, a donor–acceptor (D–A)-type COF anchored with pyridinium and quaternary ammonium, named BPDS-COF, was developed to achieve ternary synergistic antibacterial effects. The pyridinium cations generated in situ not only sterilize but also attract and accommodate electrons to thus promote the photoelectric generation of ROS. Additionally, the quaternary ammonium salts provide good antibacterial activity. The simultaneous presence of pyridinium and quaternary ammonium can enhance the hydrophilicity and bacterial adsorption and improve adsorption for oxygen to more easily generate ROS, which are beneficial to sterilization. Moreover, BPDS-COF has the potential to be used as an oral antibacterial dental filler and implant coating material. This ternary synergistic antibacterial strategy could inspire the design of other multifunctional antimicrobial COFs.