A fast, highly selective and sensitive anion probe stemmed from anthracene-oxazine conjugation with CN- induced FRET

An anthracene-oxazine conjugate was synthesized by hybridizing the fluorescent anthracene unit with the photochromic nitrosubstituted oxazine. The structure of the conjugate was established by using IR, NMR, HR-MS and single crystal X-ray crystallography. The anthracene-oxazine conjugate was evaluated for affinity towards different anions in aqueous medium and selectivity towards cyanide ion was observed through development of color visible to the naked eye as well as through changes in fluorescence signal. An excellent value of 58 nm limit of detection value was obtained, which indicated an excellent sensitivity of the probe towards cyanide ion. The probe displayed fluorescence quenching via intramolecular energy transfer from the hybridized anthracene unit to the parent oxazine photochrome upon addition of the cyanide ions in aqueous medium. DFT calculations were performed to support the experimental data. (C) 2017 Elsevier Ltd. All rights reserved.