Selective Hg2+ signaling via dithiane to aldehyde conversion of an ESIPT fluorophore

We herein report the development of a simple structured reaction-based probe for the fluorescence signaling of Hg2+ ions using a dithiane derivative of an excited-state intramolecular proton transfer (ESIPT) dye. The designed probe exhibited prominent fluorescence signaling behavior towards Hg2+ ions by the deprotection of its dithiane function to an aldehyde in an aqueous acetonitrile solution. The interfering response of Cu2+ ions was efficiently removed using citrate as both a masking agent and a buffer. Thus, the use of a citrate buffer allowed exclusive Hg2+-selective signaling to be obtaibed in the presence of common environmentally relevant transition metal ions. Signaling of the Hg2+ ions was complete within 15 min after sample preparation, and a detection limit of 2.0 x 10(-7) M was estimated. As a practical application of the designed probe, the detection of Hg2+ ions in simulated wastewater was tested using-a smartphone as a portable signal-capturing device. (C) 2016 Elsevier Ltd. All rights reserved.