Dual signaling of hypochlorite in tap water by selective oxidation of phenylselenylated dichlorofluorescein

Abstract

A novel hypochlorite-selective signaling probe based on the oxidative transformation of phenylselenylated 2',7'-clichlorofluorescein 1 to its selenoxide analogue was investigated. In a pH 7.0 phosphate buffer system (containing 1% DMF as a solubilizer), the designed probe I exhibited pronounced colorimetric and fluorogenic hypochlorite signaling behavior over other representative oxidants such as hydrogen peroxide, tert-butyl hydroperoxide, perborate, and percarbonate as well as a range of environmentally relevant metal ions and anions. The signaling was due to the hypochlorite-assisted oxidation of the probe's selenyl moiety to selenoxide. Hypochlorite signaling was unaffected by the presence of common metal ions and anions as a background. The hypochlorite-selective fluorescence signaling of probe 1 has a detection limit of 3.9 x 10(-8) M (0.002 ppm). Finally, the determination of hypochlorite concentration in tap water using a smartphone as a stand-alone portable signaling detection and processing tool was successfully demonstrated. (C) 2017 Elsevier B.V. All rights reserved.