A highly sensitive endoplasmic reticulum-targeting fluorescent probe for the imaging of endogenous HS in live cells.

Hydrogen sulfide (HS) as an important signaling biomolecule participates in a series of complex physiological and pathological processes. In situ and rapid detection of HS levels in endoplasmic reticulum (ER) is of great importance for the in-depth study of its virtual functional roles. However, the ER-targeting fluorescent probe for the detection of HS in live cells is still quite rare. Herein, a new ER-targeting fluorescent probe (FER-HS) for detecting HS in live cells was characterized in the present study. This probe FER-HS was built from the hybridization of three parts, including fluorescein-based skeleton, p-toluenesulfonamide as ER-specific group, and 2,4-nitrobenzene sulfonate as a response site for HS. The response mechanism of the probe FER-HS to HS is on the basis of the ring-opening and ring-closing processes in fluorescein moiety. Moreover, the probe FER-HS was successfully used for the imaging of exogenous and endogenous HS in ER of live cells.