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

• Published in: Dyes and pigments 2017-02, Vol.137, p.69-74
• Main Authors: Chang, In Jung, Hwang, Keum Saem, Chang, Suk-Kyu
• Format: Article
• Language: English
• Subjects: 2-Hydroxyphenyl benzothiazole; Cu2+ masking; Dithiane deprotection; ESIPT fluorophore; Hg2+ ions; Smartphone
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2016.09.058

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 obtained 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 × 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. [Display omitted] •A simple structured Hg2+-selective fluorescent sensor based on an ESIPT dye was developed.•Probe showed marked Hg2+-selective signaling via dithiane-to-aldehyde conversion.•Interfering response from Cu2+ was removed using citrate buffer as a masking agent.•Signaling of Hg2+ in simulated wastewater by readily-usable smartphone was possible.