An Endoplasmic Reticulum-Targeted Ratiometric Fluorescent Probe for the Sensing of Hydrogen Sulfide in Living Cells and Zebrafish.

Hydrogen sulfide (HS) is an endogenous gaseous signaling molecule in many physiological processes. Relevant investigations indicated that HS plays a cytoprotective effect under endoplasmic reticulum stress. Currently, it is still a challenge to design effective methods for ratio detection of endoplasmic reticulum HS. Herein we are the first to construct a ratiometric near-infrared fluorescent probe (M-HS) for sensing HS in the endoplasmic reticulum. M-HS has high selectivity and sensitivity toward HS (LOD = 39.1 nM). Additionally, M-HS possessed an excellent endoplasmic reticulum targeting ability. Moreover, M-HS was successfully utilized to visualize exogenous/endogenous HS in HeLa cells and zebrafish. Particularly important, endogenously produced HS was observed under endoplasmic reticulum stress induced by tunicamycin.