A convenient colorimetric and ratiometric fluorescent probe for detection of cyanide based on BODIPY derivative in aqueous media

A convenient colorimetric and ratiometric fluorescent probe based on BODIPY derivative for cyanide detection has been synthesized, whose structural contains a dicyanovinyl group used as a sensing unit. Among the tested analytes, such as CN⁻, F⁻, Cl⁻, Br⁻, I⁻, ClO₄⁻, AcO⁻, NO₃⁻, H₂PO₄⁻ HSO₄⁻, S₂⁻ and N₃⁻, only CN⁻ could react with dicyanovinyl moiety by nucleophilic addition, which disrupted the π-conjugation of the probe and hindered the intramolecular charge transfer (ICT), leading a blue shift of absorption and fluorescence spectrum and a concomitant color change from yellow to light pink. The detection limit of this probe was calculated to be 0.98 μM, which is lower than the maximum concentration in drinking water (1.9 μM) permitted by the World Health Organization (WHO). Moreover, the probe showed excellent selectivity and anti-interference ability towards CN⁻ over other anions. The reaction mechanism was fully supported by ¹H NMR and MS spectrum.