A fluorescent photosensitizer with far red/near-infrared aggregation-induced emission for imaging and photodynamic killing of bacteria.

Abstract Bacterial infection poses great threats to human health and the emergence of drug-resistant bacteria requires effective methods to eliminate bacteria and avoid bacterial resistant. Photodynamic therapy (PDT), which applies photosensitizers (PSs) to generate reactive oxygen species (ROS) under light irradiation, has attracted widespread concern on bacterial treatment, recently. In this work, we develop a far red/near-infrared (FR/NIR)-emissive fluorescent molecule, AIE-TEA , with aggregation-induced emission (AIE) characteristics, for FR/NIR imaging and PDT of bacteria. Due to AIE characteristics and a certain degree of water dispersity, the AIE-TEA can conduct imaging of bacteria without wash process. Moreover, the AIE-TEA can effectively generate ROS under ultralow power white light irradiation (20 mW cm−2) with quantum yield of up to 83%, which is crucial for PDT of bacteria. The AIE-TEA can selectively kill Gram-positive bacteria (S. aureus) via image-guided PDT. Graphical abstract Image 1 Highlights • A FR/NIR fluorescent photosensitizer with aggregation-induced emission property. • The photosensitizer can conduct imaging of bacteria without wash process. • The photosensitizer can effectively generate ROS under ultralow power white light irradiation with quantum yield of 83%. • The photosensitizer can selectively kill Gram-positive bacteria (S. aureus) via image-guided PDT. [ABSTRACT FROM AUTHOR]