Red-emitting fluorescent probe for detecting hypochlorite acid in vitro and in vivo

Due to the importance of hypochlorous acid (HClO) in biological and industrial, development of fluorescent probes for HClO has been an active research area. Here, a new red-emitting ratiometric fluorescent probe (P) was synthesized and well defined characterization via NMR, HR-MS, and fluorescence spectrum, which serves as a selective and sensitive probe for ClO− group. The probe showed a ratiometric fluorescent response to hypochlorite at the emission intensities ratio (I480/I612) increasing from 0.28 to 27.46. The emission intensities ratio (I480/I612) was linearly enhanced (I480/I612 = 0.064 X + 0.096) with the ClO− concentration range from 1 to 30 μM. The detection limitation for ClO− in aqueous solution is 0.47 μM. Moreover, this biocompatible red-emitting ratiometric fluorescent probe was utilized to the fluorescence imaging of ClO− in living cells and Zebrafish.