A dual-channel and fast-response fluorescent probe for selective detection of HClO and its applications in live cells

In this work, a novel water-soluble fluorescent probe (BODIPY-P) was designed and synthesized for HClO detection. The probe exhibited ratiometric fluorescence variation with rapid response upon addition of NaClO in deionized water (PBS buffer, pH 7.4) and the change of fluorescence color from red to orange was distinguishable by the naked eyes. The ratio of fluorescence intensity (F-567/F-629) gradually increased and showed a good linear correlation with HClO concentration in the range of 0-5 eq. The detection limit was estimated to be 31.6 nM, which enables the quantitative detection of trace amount of HClO realizable. Fluorescence titration experiments demonstrated that the probe was highly selective and competitive over other ROS, biothiols, common anions, physiological relevant cations. The recognition mechanism of the probe towards HClO was proved to be HClO-promoted oxidative cleavage of olefinic C=C double bond. Most importantly, the fluorescence imaging of BODIPY-P in L929 cells suggested that the probe was cell membrane permeable and low toxic, which was capable of monitoring exogenous and endogenous HClO within a few seconds.