Colorimetric fluorescent cyanide chemodosimeter based on triphenylimidazole derivative

•A triarylimidazole-based colorimetric chemodosimeter for CN− was demonstrated.•The chemodosimeter can recognize CN− with obvious color and fluorescence change.•The chemodosimeter exhibits a very low limit of detection (0.11 μM) for CN−.•The chemodosimeter allows naked eye detection of CN−.

In this paper, we demonstrated a highly selective colorimetric chemodosimeter for cyanide anion detection. This chemodosimeter having a triphenylimidazole group as a fluorescent signal unit and a dicyano-vinyl group as a reaction unit was synthesized by the Knoevenagel condensation of 4-(4,5-diphenyl-1H-imidazol-2-yl)benzaldehyde with malononitrile in a reasonable yield. The probe exhibited an intramolecular charge transfer (ICT) absorption band at 420 nm and emission band at 620 nm, respectively. Upon the addition of cyanide anion, the probe displayed a blue-shifted spectrum and loss in color due to the disruption of conjugation. With the aid of the fluorescence spectrometer, the chemodosimeter exhibited a detection limit of 0.11 μM (S/N = 3). Interferences from other common anions associated with cyanide anion analysis were effectively inhibited.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide