A NIR fluorescence probe having significant fluorescence turn-on signal at 700 nm and large Stokes shift for rapid detection of HOCl in vivo.

With a hybrid coumarin-dicyanoisophorone as report unit and dimethylthiocarbamate as response site, a novel reaction-based fluorescence probe (CDCI-HClO) was synthesized herein for rapid detection of hypochlorous acid (HOCl). CDCI-HClO can respond to HOCl quickly (almost in seconds), selectively, and sensitively, and give an obviously enhanced signal of near-infrared fluorescence at 700 nm. The detection limit of CDCI-HClO for HOCl is about 4 nM. Moreover, with the merit of a large Stokes shift (190 nm), CDCI-HClO was successfully applied to the imaging of HOCl in live cell, zebrafish, and living mice. All results demonstrated that CDCI-HClO is a valuable new NIR fluorescence imaging tool to detect hypochlorous acid in living systems.