In recent decades, there has been a significant focus on the development of organic thermally activated delayed fluorescence (TADF) materials as potential emitters for use in organic light-emitting diodes (OLEDs) and sensors, as well as acting as photocatalysts. Notably, the delayed fluorescence of TADF materials makes them well-suited to their use in time-resolved fluorescence imaging (TRFI) studies. This is because the long lifetimes of the TADF materials can address signalto-noise issues associated with discriminating the dye signal from the autofluorescence of biological systems. An ideal TADF probe should have a sufficiently long emission lifetime (> 10 ns), suitable biocompatibility, and a tolerance to both atmospheric and intracellular oxygen such that its excited state is not too readily quenched by this species.