A ratiometric fluorescent probe for rapid and specific detection of hypochlorite

Hypochlorite (ClO−), an important reactive oxygen species, plays a crucial role in vitro and vivo. In this work, a ratiometric fluorescent probe (TPAM) was designed and synthesized for sensing ClO− based on substituted triphenylamine and malononitrile, which exhibited obvious color change from orange to colorless under daylight accompanied by noticeable fluorescence change from red to green in response to ClO−. The TPAM could quantitatively determine the concentrations of ClO− with the merits of fast response, excellent selectivity, high sensitivity and low detection limit of 0.1014 μM. 1H NMR, mass spectrum and theoretical calculations proved that ClO− triggered the oxidation cleavage of the carbon-carbon double bond in TPAM, resulting in significant changes in color and fluorescence. In addition, TPAM was successfully applied for imaging ClO− in living cells with good photostability and biocompatibility.