Fast detecting hypochlorous acid based on electron-withdrawing group promoted oxidation and its biological applications in cells and root tips of plants

Hypochlorous acid, a type of reactive oxygen species, has been shown to play an important role in organisms. Nowadays, there are many kinds of fluorescence detecting mechanisms to detect hypochlorous acid in vivo. Due to the high selectivity, the mechanism of using the strong oxidation of hypochlorous acid to break carbon‑carbon double bonds has been favored by many scientists. However, the reported probes of breaking carbon‑carbon double bonds still had drawback such as slow response. Based on this, we introduced electron-withdrawing group malonitrile to accelerate the oxidation of hypochlorous acid, resulting in reaction time less than 150 s. Meanwhile, the probe exhibited excellent selectivity, optical stability, high sensitivity and the detection limit as low as 0.19 μM. More importantly, we also successfully proved the potential application of the probe for the detection of intracellular ClO- living cells and Arabidopsis root tip by fluorescence imaging.