A Dicyanovinyl-Substituted D-π-A Type Chemosensor for Selective and Sensitive Detection of Cyanide Ions in H₂O/DMSO...

The detection of hazardous analytes such as CN⁻, N₂H₄, and ClO⁻ is of great importance due to their potential risks to human health and the environment. Although numerous fluorescent sensors have been developed for the determination of these species, most studies have focused on individual analytes; conversely, the simultaneous evaluation of CN⁻, N₂H₄, and ClO⁻ considering them as potential interfering species has received relatively limited attention. Therefore, in this study, a dicyanovinyl-substituted D-π-A type organic material (TPA-Th-DCV) was developed as a fluorescent sensor exhibiting a rapid response, high selectivity, and excellent sensitivity toward cyanide ions (CN⁻) even in the presence of other anions (N₂H₄, ClO⁻ and etc.). The photophysical behavior of TPA-Th-DCV was significantly altered by the nucleophilic addition of CN⁻ to its vinyl group, which disrupted the intramolecular charge transfer (ICT) process. Fluorescence measurements revealed a remarkably low limit of detection (LOD) of 48 nM. The sensing mechanism of TPA-Th-DCV toward CN⁻ was elucidated through NMR spectroscopy, mass spectrometry, and DFT/TDDFT calculations. Moreover, the turn-on fluorescence response of TPA-Th-DCV enabled the successful detection of cyanide in common food samples, demonstrating its strong potential for real-world environmental and food safety monitoring applications.