Development of a novel benzothiadiazole-based fluorescent turn-on probe for highly selective detection of glutathione over cysteine/homocysteine

Abstract Biothiols, such as glutathione (GSH), cysteine (Cys), homocysteine (Hcy), plays crucial roles in biological systems due to their physiological and pathological functions. So it is of great interest to develop new fluorescence sensing systems for distinguishing between them. Herein we report a novel fluorescent turn-on probe for selective sensing of GSH over Cys/Hcy with high selectivity and sensitivity. The sensing behavior of ATD-Cl toward GSH and Cys/Hcy is completely different from most of the previous reported NBD-based fluorescent probes. The detection limit of ATD-Cl for GSH is found to be 89 nM. Cell imaging experiments demonstrate that ATD-Cl possesses excellent cell permeability and can be employed to image GSH in living MCF-7 cells.