A cyanine-based near-infrared fluorescent probe for highly sensitive and selective detection of hypochlorous acid and bioimaging.

Hypochlorous acid (HOCl) is a kind of reactive oxygen species which plays an important role in biological process. HOCl detection is of great importance in disease prevention and treatment. Herein, a cyanine-based near-infrared (NIR) fluorescent probe for HOCl has been designed and synthesized. This probe can react with HOCl in a dose-response manner along with the fluorescence of the probe quenched, the reaction through an electrophilic addition to the double bond and subsequent oxidation reaction. Experiments indicate that the probe can be acted as a selective and sensitive indicator for HOCl and the limit of detection for HOCl is estimated to be 22nM. What's more, this probe shows a low toxicity to cells and can be applied to visualize HOCl molecules in living cells. Therefore, the proposed method may make a significant contribution to HOCl detection.