Naphthol-naphthalimide based ‘turn-on’ fluorescent sensor for ClO− in aqueous media and test kit

A novel naphthol-naphthalimide-based fluorescent chemosensor CGB (N-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)-3-hydroxy-2-naphthamide) for ClO− was synthesized. Sensor CGB can detect ClO− by a fluorescent turn-on method. The detection limit is calculated to be 10.67 μM. CGB showed a remarkable selectivity for ClO− over diverse competing anions including reactive oxygen species (ROS) via deprotonation reaction. Additionally, sensor CGB was well applied as a fluorescent test kit for the determination of ClO−. Sensing mechanism of CGB to ClO− was demonstrated by fluorescent and UV–vis spectroscopy, ESI-mass, NMR titration and DFT calculations.