A p-toluenesulfonamide-modified benzo[h]chromene hydrazone: Fluorescent turn-on detection of hypochlorite and its application to imaging the endoplasmic reticula of living cells and zebrafishes.

[Display omitted] • A benzo[ h ]chromenen-based acetylhydrazone probe 1 containing a toluene sulfonamide group is reported. • Probe 1 showed rapid response (less than 30 s), low detection limit (0.34 μM) and high selectivity for ClO− detection. • Probe 1 can specifically image endogenous and exogenous ClO− in the endoplasmic reticulum of HeLa cells and zebrafish. Hypochlorite (ClO−) is a ROS that plays a crucial role in the immune system in the body. As the largest organelle in the cell, the endoplasmic reticulum (ER) manages various life activities. Thus, a simple hydrazone-based probe was designed, which provided a fast turn-on fluorescent response toward ClO−. With a terminal p -toluenesulfonamide group as the endoplasmic reticulum (ER)-specific site, probe 1 was mainly accumulated at ER of living cells, and could be used for imaging endogenous and exogenous HClO in cells and zebrafishes. [ABSTRACT FROM AUTHOR]