Pyridine-coumarin chemosensor for selective determination of CN⁻ ions in water and organic media via ester bond cleavage

This study focuses on the effective sensing of common ions by developing a coumarin-based chemosensor. In this study, a novel pyridine–coumarin conjugate (1) was synthesized and characterized for the selective and sensitive detection of CN⁻ ions in water. The structure of the chemosensor was confirmed by ¹H NMR, ¹³C NMR, and mass spectrometric analyses. Spectroscopic measurements in water indicated the selective fluorimetric sensing of CN⁻ ions with a limit of detection of 29 nM. In contrast, in acetonitrile, 1 revealed significant bathochromic shifts and increased fluorescence in the presence of CN⁻ and F⁻, with 0.24 nM and 2.17 nM limit of detection, respectively.