A Colorimetric and Fluorescent Probe Based on Quinoline‐Indolium for Detection of CN⁻ in Aqueous Media

Abstract

A new colorimetric and fluorescent probe (QI) based on quinoline-indolium was developed for detection of CN À . In an aqueous solution, QI showed high selectivity and strong antiinterruption for CN À . In addition, it was clearly visible to the naked eyes that the color and fluorescence changes induced by CN À exhibited sharp contrast. The research also found that QI could determine CN À in the range of pH 5-10. The spectral signal was linearly proportional to CN À concentration, and the detection limit was calculated to be low as 41.6 nM. The sensing mechanism of QI to CN À was accomplished via the attachment of CN À at the C atom of indolium salt C=N + group through the nucleophilic addition, which was confirmed by 1 H NMR studies. Notably, we could apply the designed probe for the cycle detection of CN À in a wide pH range, for practical purposes for a long duration. Furthermore, the TLC plates of QI were verified to detect CN À in a simple, rapid way in environmental systems.

A New Phenothiazine-Based Fluorescent Sensor for Detection of Cyanide

“…CN − in the human body would prevent Fe 3+ from being reduced to Fe 2+ , which inhibits the transmission of electrons and affects cell respiration, and then damages the central nervous system, which is most sensitive to hypoxia, causing vomiting, coma and even suffocation [5][6][7]. Research shows that the lethal concentration of cyanide to the human body is only 0.5-3.5 mg/kg, so CN − detection is of great significance in many research fields and it is urgent to develop convenient and effective CN − detection methods [8][9][10][11]. Fluorescence sensors, as a new detection method, have been widely used in the detection of CN − because of their good sensitivity, selectivity and rapid response [12][13][14][15][16][17][18][19].…”

Idiosyncatic recognition of Zn2+ and CN− using pyrazolyl-hydroxy-coumarin scaffold and live cell imaging: depiction of luminescent Zn(ii)-metallocryptand

“…Polypodal Schiff bases may synthesize multinuclear metallo–macrocycle complexes, 1,2 which may act as potential magnetic materials, 3,4 homogeneous catalysts, 5 optical and electronic materials, 6,7 sensing devices, 8 etc . Schiff bases with fluorogenic components such as carbazole, 9,10 quinoline, 11,12 rhodamine, 13,14 naphthyl, 15,16 pyrenyl, 17,18 fluorenyl, 19,20 and diformyl 21,22 influence the emission energy, intensity, pattern, and the molecules might serve as sensitive detectors of ions/molecules. Fluorogenic units of Coumarin derivatives 23–25 are beneficial for their diverse pharmacological properties, low toxicity, and interesting photophysical responses to analytes.…”