Unique Fluorogenic Ratiometric Fluorescent Chemodosimeter for Rapid Sensing of CN⁻in Water

A new benzimidazole‐spiropyran conjugate chemosensor molecule ( BISP ) has been synthesized and characterized by 1 H NMR spectroscopy, mass spectrometry (ESI‐MS), and elemental analysis. The two isomeric forms ( BISP ↔ BIMC ) were shown to be highly selective and sensitive to CN − among the ten anions studied in aqueous HEPES buffer, as shown by fluorescence and absorption spectroscopy and even by visual color changes, with a detection limit of...