A Fluorescent Probe with a Significant Selective Turn-On Response for HClO Detection and Bioimaging in Living Cells

Hypochlorous/Hypochlorite(HClO/ClO-) plays an important biochemistry roles in normal operation of the life system. Herein, a fluorescent probe 7-chloro-3-((E)-3-(4-(dimethylamino)phenyl)- acryloyl)-2H-chromen-2-one (CCO) was rationally designed and synthesized via aldehyde ketone condensation reaction to detect ClO- in Tris-HCl (pH=7.2, 60% DMF) solution. Probe CCO was cleaved conceivably in the coumarin lactone ring by an oxidation reaction with ClO- and emitted intensive bright yellow fluorescence. The sensing mechanism was further confirmed by ESI-MS and DFT calculation. The fluorescence emission of probe CCO triggered by ClO- was obviously enhanced within 20 s. The limit of detection of probe CCO was calculated as low as 2.6 nM. Furthermore, probe CCO can be given as an effective and outstanding fluorescent exogenous ClO- probe in living HEK293T cells for microscopic cell imaging.