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

Hydrogen sulfide (H2S) is an endogenous gaseous signaling molecule in many physiological processes. Relevant investigations indicated that H2S plays a cytoprotective effect under endoplasmic reticulum stress. Currently, it is still a challenge to design effective methods for ratio detection of endoplasmic reticulum H2S. Herein we are the first to construct a ratiometric near-infrared fluorescent probe (M-H2S) for sensing H2S in the endoplasmic reticulum. M-H2S has high selectivity and sensitivity toward H2S (LOD = 39.1 nM). Additionally, M-H2S possessed an excellent endoplasmic reticulum targeting ability. Moreover, M-H2S was successfully utilized to visualize exogenous/endogenous H2S in HeLa cells and zebrafish. Particularly important, endogenously produced H2S was observed under endoplasmic reticulum stress induced by tunicamycin.