Photometric and Colorimetric Cyanide Detection Sensor Using Amine Based Nitrobenzoxadiazole Derivatives

Abstract

AbstractThe fluorescent probes 7‐nitro‐N‐phenylbenzo[c][1,2,5]oxadiazol‐4‐amine (1), and 4‐((7‐nitrobenzo[c][1,2,5]oxadiazol‐4‐yl)amino)benzonitrile (2) were synthesised for the detection of cyanide ion (CN−). A new correlative approach with nitrobenzoxadiazole (NBD)‐based probes to detecting CN− by the Donor‐Acceptor D‐A (1) and Acceptor‐Donor‐Acceptor (A‐D‐A) (2) with the aid of DFT calculations are reported. Given their design features, these NBD probes 1 and 2 provide useful insights into the dual‐channel (fluorometric and colorimetric) sensor activity with good selectivity for CN− detection, considerable fluorescence amplification in the presence of CN− ion, and the desirable “Off–on” fluorescent responses toward CN− in the semi‐aqueous medium. The photophysical studies confirmed the A‐D‐A type molecule has a detection limit 0.163 μM for CN− sensing, which is lower than the WHO′s cyanide in water permitted limit. The simple synthetic probes 1 and 2 will offer up new possibilities for industrial effluent CN− detection and bio‐imaging of CN− in a variety of cell lines. This will undoubtedly aid in the understanding of the basic mechanism of CN− poisoning in the bloodstream.