Wash-Free Bacterial Gram-Typing and Photodynamic Inactivation with Long-Chain-Tailed BODIPY Derivatives

The rapid identification of bacterial Gram types and their viability, as well as efficient bacterial elimination are crucial for managing bacterial infections yet present important challenges. In this research, we utilized long-chain-tailed BODIPY derivatives to address these hurdles. Our data indicated that these derivatives can distinguish bacteria types and their viability in aqueous solutions through a concise turn-on fluorescent response. Among them, B-8 stained both live and dead bacteria, and B-14 offered a wash-free staining. B-18 demonstrated the highest affinity to selectively fluorescent label viable gram-positive bacteria with a 53.2-fold fluorescent enhancement. Confocal imaging confirmed that B-18 can serve as an effective membrane-specific probe for facilitating the typing between gram-negative and gram-positive bacteria in a wash-free manner. Additionally, B-18 displayed selective photodynamic inactivation at 1 μM toward gram-positive bacteria. In vivo studies variformed the ideal photodynamic therapeutic efficacy of B-18 against methicillin-resistant Staphylococcus aureus in mice wound infections.