Fig. 1. (a) Representative photophysical pathways of an organochalcogen chromophore/fluorophore include absorption, fluorescence, intersystem crossing (ISC), reverse ISC, phosphorescence, and non-radiative decay. (b) Representative photophysical pathways of an organochalcogen fluorescent probe that is off when non-radiative decay occurs through triplet quenching, and on when Förster Resonance Energy Transfer (FRET) occurs to a fluorescent acceptor.
