Rational design of an ESIPT-based fluorescent probe for selectively monitoring glutathione in live cells and zebrafish.

Abstract Glutathione (GSH), an extremely important antioxidant, is a major participant in maintaining redox homeostasis and tightly associated with various clinical diseases. Thus, accurate and rapid detection of intracellular GSH is imperative to elucidate its role in physiological and pathological processes. Herein, by modifying 2-(2′-hydroxyphenyl) benzothiazole (HBT) scaffold, we developed an excited-state intramolecular proton transfer (ESIPT)-based fluorescent probe BTFMD for tracking GSH, which exhibited good selectivity, excellent water solubility, a large Stokes shift (181 nm) and fast response rate (within 10 min). Furthermore, the probe was successfully applied for imaging of endogenous GSH in live cells and zebrafish, and probing into the role of GSH in the development of cancer and Parkinson's disease.