title: Ratiometric fluorescent/colorimetric cyanide-selective sensor based on excited-state intramolecular charge transfer-excited-state intramolecular proton transfer switching.
abstract: A novel salicylideneaniline-based fluorescent sensor, SB1, with a unique excited-state intramolecular charge transfer-excited-state intramolecular proton transfer (ESICT-ESIPT) coupled system was synthesized and demonstrated to fluorescently sense CN(-) with specific selectivity and high sensitivity in aqueous media based on ESICT-ESIPT switching. A large blue shift (96 nm) was also observed in the absorption spectra in response to CN(-). The bleaching of the color could be clearly observed by the naked eye. Moreover, SB1-based test strips were easily fabricated and low-cost, and could be used in practical and efficient CN(-) test kits. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations further support the cyanide-induced ESICT-ESIPT switching mechanism. The results provide the proof of concept that the colorimetric and ratiometric fluorescent cyanide-selective chemodosimeter can be created based on an ESICT-ESIPT coupled system.
authors.affiliation: Department of Chemical Engineering, Feng Chia University , 40724 Taichung, Taiwan ROC.
authors.forename: Wei-Chi
authors.initials: WC
authors.lastname: Lin
authors.forename: Sin-Kai
authors.initials: SK
authors.lastname: Fang
authors.forename: Jiun-Wei
authors.initials: JW
authors.lastname: Hu
authors.forename: Hsing-Yang
authors.initials: HY
authors.lastname: Tsai
authors.forename: Kew-Yu
authors.initials: KY
authors.lastname: Chen
mesh_terms: D003124:Colorimetry; D003486:Cyanides / Q000032:analysis*; D005456:Fluorescent Dyes; D011522:Protons; D013050:Spectrometry, Fluorescence
chemical_list: D003486:Cyanides; D005456:Fluorescent Dyes; D011522:Protons