A ratiometric fluorescent probe for rapid and specific detection of hypochlorite

Hypochlorite (ClO^- ), as a kind of essential reactive oxygen species, plays a crucial role in vitro and in vivo. Here, a ratiometric fluorescent probe (TPAM) was designed and constructed for sensing ClO^- based on substituted triphenylamine and malononitrile, which exhibited obvious colour transfer from orange to colourless under daylight accompanied by noticeable fluorescence change from red to green in response to ClO^- . TPAM could effectively monitor ClO^- with the merits of fast response, excellent selectivity, high sensitivity and a low detection limit of 0.1014 μM. ¹ H NMR, mass spectra and theoretical calculations proved that ClO^- caused the oxidation of the carbon-carbon double bond in TPAM, resulting in compound 1 and marked changes in colour and fluorescence. In addition, TPAM was utilized for imaging ClO^- in living cells successfully with good photostability and biocompatibility.