Organic Afterglow Vesicles

Organic afterglow materials hold great promise for applications in bioimaging, sensing, and information encryption, yet the construction of advanced nanostructures like vesicles with long-lived luminescence remains a formidable challenge. We pioneer the construction of organic afterglow vesicles via polymerization-induced self-assembly (PISA), integrating a thermally activated delayed fluorescence (TADF)-type organic afterglow emitter into block copolymer nanostructures. The resulting vesicles exhibit well-defined hollow morphologies, uniform size distribution, and high solid content up to 20%. They display significant room-temperature afterglow with an emission lifetime exceeding 200 ms and a photoluminescence quantum yield (PLQY) of 20.8%. The afterglow mechanism is attributed to efficient TADF with a moderate intersystem crossing rate, where the triplet excited states are excellently protected by the rigid glassy vesicle walls. Moreover, the vesicles show rapid, reversible, and repeatable oxygen-responsive behavior, making them promising for reusable oxygen sensing. This work establishes a versatile and scalable strategy for designing functional organic afterglow nanostructures with potential applications in bioimaging, sensing, and environmental monitoring.