Delayed Fluorescence Materials: Mechanism, Design, and Bioapplication

Materials with delayed fluorescence (DF) are characterized by an available triplet state and prolonged fluorescence lifetime. In particular, those thermally activated delayed fluorescence (TADF) materials are representative of those that have been well investigated and developed. The features of DF materials ensured their impressive photophysical properties and device performances in various areas of optoelectronic applications. Recently, researchers began to apply them into biological fields and achieved great developments in bioapplications. In this Review, typical design strategies for DF molecules were presented, and some recently published TADF and aggregation-induced DF (AIDF) materials within biological fields, involving fluorescent biosensing, time-gated bioimaging, and photodynamic therapies, were systematically summarized. Furthermore, future perspectives of DF materials in biological fields were discussed, and aspects of enhancements were proposed.