Optical, electrochemical, and test strip methods for sensitive and selective detection of Cyanide ion using a multifunctional ?-extended azaacene-based system

A reversible multichannel chemosensor IPBTO [E)-5-(4-(1H-imidazo[4,5-b]phenazin-2-yl) benzylidene)-2-thioxothiazolidin-4-one] was fabricated as a D-pi-A system and used for the detection of cyanide ion (CN-) in aqueous solutions. This chemosensor exhibited a switch-off fluorescence response at 566 nm for CN- in the presence of other tested anions. The detection limit of IPBTO toward CN- was 0.7 mu M with the association constant being 2.0 x 106 M-1. The reversibility and reusability aspects of this chemosensor were investigated for five consecutive runs, and good results were obtained. In addition, IPBTO as a bioimaging agent with good cell viability was deployed for the detection of CN- in MDA-MB-231 cells. Excellent potential for sensing CN- was also realized for this chemosensor in food and environmental samples. Besides, IPBTO was self-assembled on the gold electrode surface (Au-IPBTO SAM) and used for accumulation and detection of CN- in aqueous media. This modified electrode was characterized by ATR surface analysis, and the electrochemical behavior of the electrode was studied utilizing cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Our results have conclusively revealed that this electrochemical sensor could be successfully used to detect CN-.