Endoplasmic reticulum targeted fluorescent probe for the detection of hydrogen sulfide based on a twist-blockage strategy.

Hydrogen sulfide (H2S) is very important for humans and is involved in many physiological processes. Here, we designed and reported a new naked-eye colorimetric fluorescent probe Z1 for detecting H2S in absolute HEPES solution. The fluorescence intensity, after the reaction of the probe and H2S, is about 32 times that of the probe alone. When the concentration of H2S is 0-100 μM, the detection limit (DL) is rather low at about 0.15 μM (3σ/slope). The response mechanism is based on the leaving of the 2,4-dinitrobenzene moiety, followed by intramolecular cyclization to give a fluorescent iminocoumarin-benzothiazole group. Moreover, Z1 was applied to endogenous and exogenous H2S imaging in living cells. The high overlap coefficient proved that probe Z1 has good ER-tracker localization in living cells.