Thermally activated delayed fluorescence (TADF) emitters are a class of emissive compounds that have small singlet-triplet excited state energy gaps (DEST). They have garnered much attention due to their capacity to harvest both singlet and triplet excitons to produce light in electroluminescent devices such as organic light-emitting diodes (OLEDs). They have increasingly been used in other applications, most notably as photocatalysts and as bioimaging reagents. However, very few reports exist documenting the use of organic TADF materials as sensors. The first reported example employed a TADF compound, acridine yellow (Figure ), as a temperature sensor. Steinegger et al. subsequently reported a series of carbazolesubstituted dicyanobenzene and diphenylamine-substituted anthraquinone donor-acceptor (D-A) TADF emitters, such as compound a3 (Figure ), for use as oxygen and temperature sensors. In doped films, these dyes exhibit a temperature sensitivity in the investigated temperature range (278-323 K), showing a 1.4 to 3.7% K -1 change of the delayed lifetime, compared to that at 298 K. Tonge et al. disclosed a TADF polymer, PTZ-ODA (Figure ), which acts as a singlecomponent ratiometric oxygen sensor. In addition to oxygen and temperature sensors, Li et al. developed a sensor for solvent polarity based on compound 3 (Figure ), which shows dual emissions at 332 nm (strong LE fluorescence) and 435 nm (weak CT TADF) in DCM under air.