A novel carbazole-benzothiazole-based chemodosimeter for the chromogenic and fluorogenic recognition of CN??

New Journal of Chemistry Pub Date: 2023-05-17 DOI: 10.1039/D3NJ01157G

Abstract

A novel colorimetric and fluorescent sensing probe, (E)-3-(4-(9H-carbazol-9-yl)phenyl)-2-(benzo[d]thiazol-2-yl)acrylonitrile (CBTA), was synthesized and characterized by spectroscopic techniques. CBTA displayed “turn off” fluorescence in the presence of cyanide with a higher selectivity than that of others anions such as Br?, Cl?, I?, NO3?, SO42?, SCN?, CO32?, N3?, OH?, HCO3?, H2PO4?, HPO42?, F?, ACO?, and PO43? in a DMSO?:?H2O medium (40?:?60, v/v, HEPES buffer, pH = 7.2). The “turn off” fluorescence response mechanism can be attributed to the intra-molecular charge transfer (ICT) process, which is blocked by the nucleophilic attack of cyanide ions at the cyano vinyl group of the probe. The LOD was found to be 3.57 × 10?8 M. The interaction involved behind the sensing of cyanide was investigated by Job's plot analysis, 1H-NMR, and mass spectroscopic studies. DFT and TDDFT were also employed to verify the experimental outcomes. Moreover, the test strip experiment provides a wide application prospect of the receptor for detecting poisonous cyanide in the environment and biological system.

Graphical abstract: A novel carbazole-benzothiazole-based chemodosimeter for the chromogenic and fluorogenic recognition of CN?
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