A tosylhydrazone-based probe for the ratiometric fluorescent detection of hypochlorite in endoplasmic reticulum of living cells

The endoplasmic reticulum (ER) is the largest organelle in the cell and is associated with the synthesis of biological proteins, while the abnormal accumulation of HClO may damage such proteins. Herein, a relatively simple tosylhydrazone probe (1) was designed for the detection of ClO- via ratiometric fluorescent signals in a semi-aqueous solution. The free probe displays a blue emission at 475 nm, while a new fluorescent band at 525 nm occurred upon the addition of ClO (-). This ratiometric signal F-525/F-475 is highly selective and sensitive toward ClO (-), with a limit of detection being 10.1 nM. Finally, the probe can be used for imaging exogenous and endogenous ClO -in ER of HeLa cells. (c) 2022 Elsevier B.V. All rights reserved.