Uncovering Light-Induced Emission Enhancement in a Dual-Emissive Photosensitizer for Real-Time Photodynamic Theranostics

Abstract

Photodynamic therapy (PDT) stands out as a promising alternative for cancer treatment due to its low invasiveness and low side effects. Additionally, photosensitizers often exhibit photoluminescent properties, which provide valuable diagnostic guidance for preoperative planning and drug delivery. However, current assessment of therapeutic efficacy largely relies on auxiliary imaging techniques to track tumor volume changes, which fail to provide realtime feedback on treatment outcomes. In this study, a DNA-specific dual-emissive photosensitizer, TPBT, was identified for photodynamic theranostics with red fluorescence serving for preoperative guidance and green fluorescence enabling real-time therapeutic evaluation. Notably, TPBT can behave as a cell-membrane permeable dye to stain the nuclei of early apoptosis cells. Moreover, TPBT exhibits a unique "light-induced emission enhancement" phenomenon, where its green fluorescence intensity is amplified by 2 approximately threefold under light exposure, enabling more accurate signal reporting and reducing photobleaching. The dual-emissive TPBT integrates diagnostic imaging, personalized treatment, and real-time therapeutic monitoring into a single molecule, offering an innovative strategy for developing efficient and precise theranostic systems.