A biginelli-azophenol based robust sensor for rapid diagnosis of cyanide in real samples

Abstract

The self-aggregation of multifunctional Biginelli-azophenol (Ligand1) in water (ONPs) led to sensitive and selective detection of toxic pollutant cyanide in an aqueous medium and solid matrix. The origin behind the excellent sensing performance of Ligand1 is assessed by 1 H NMR spectroscopy which confirmed the deprotonation of OH and simultaneous H-bond formation by cyanide with NH of Ligand1. Furthermore, the UV–Visible absorption titration studies resulted in two isosbestic points at λmax 399 nm and 314 nm, which also confirmed the complex formation between Ligand1 and CN− with the detection of the lowest concentration of cyanide at 14.5 nM. Additionally, the colorimetric detection was supported by RGB color quantification as well as a thin column impregnated with Ligand1, which gives high-performance on-site cyanide detection in real water samples. Remarkably, such a cost-effective, robust colorimetric sensor having several key features, offered novel opportunities for real-time cyanide monitoring in polluted water and hence, this makes it unique among the other reported sensors for the same.