A novel ratiometric fluorescent probe for the selective determination of HClO based on the ESIPT mechanism and its application in real samples

Based on the ESIPT fluorescence mechanism, herein, a novel ratiometric fluorescent probe was designed and synthesized for the detection of HClO. The reaction site of diaminomaleonitrile at the ortho-position of the phenolic hydroxyl group made the probe exhibit a ratiometric fluorescence response towards hypochlorous acid (HClO). The specific sensing mechanism was verified via MS, HPLC and 1H NMR spectroscopy. Moreover, the probe showed excellent performance with high sensitivity and good selectivity towards HClO in the presence of other reactive oxygen species. In addition, the probe was successfully applied to detect HClO spiked in tap water, river water and diluted human serum with good recoveries.