Dual signaling of hypochlorous acid by desulfurization of thiocoumarin

The HOCl-selective signaling behavior of thiocoumarin was investigated. The thio derivative of ethoxycoumarin showed selective and efficient colorimetric and fluorogenic signaling behaviors over other commonly used oxidants in an aqueous environment. The signaling is due to the oxidative desulfurization of the thiocarbonyl moiety by HOCl to yield oxocarbonyl function. The interference from Hg2+ ions was successfully removed by using bromide ions as a masking agent. HOCl signaling with a detection limit of 8.3 × 10−7 M in the presence of common metal ions and anions as background was possible. The designed probe could be useful for the determination of hypochlorous acid in chemical and environmental samples.