A benzothiazole-based fluorescent and colorimetric probe for the detection of ClO- and its application to zebrafish and water sample.

A benzothiazole-based fluorescent and colorimetric chemosensor BZD ((E)-2-(benzo[d]thiazol-2-yl)-5-((4-(diethylamino)-2-hydroxybenzylidene)amino)phenol) was applied for detecting ClO-. BZD showed fluorescence quenching and color variation for ClO- via oxidative reaction between ClO- and the imine bond. It could effectively detect ClO- over various competitive analytes. Detection limit for ClO- was calculated to be 1.74 μM by fluorescent method and 16.44 μM by colorimetric one, respectively. Additionally, BZD could be utilized for sensing ClO- in zebrafish, real water sample and paper strip. The photophysical characteristics and sensing mechanism of BZD to ClO- were studied by fluorescent and UV-visible spectroscopy, NMR titration, and ESI-mass spectrometry.