Colorimetric and fluorimetric detection of CN– ion using a highly selective and sensitive chemosensor derived from coumarin-hydrazone

Abstract

Novel chemosensors, including coumarin hydrazide, were designed and synthesized by a three-step synthesis sequence starting from 7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide. General spectroscopic methods (FT-IR, 1H/13C NMR, and HRMS) were used to characterize all produced chemosensors. These chemosensors demonstrate the ability to detect cyanide (CN–) anion by shifting absorption and fluorescence turn-off response in DMSO. The reaction mechanism between the synthesized chemosensors and the CN– anion involves deprotonation and addition processes; as determined by dipole-dipole interactions, reversibility, 1H NMR experiments, and theoretical studies. With limit of detection (LOD) values of 0.25 μM and 0.15 μM for 3a and 3b, respectively, these chemosensors exhibit exceptional detection ability and demonstrate the high effectiveness of their use for CN– anion determination.