Detection of cyanide ion in aqueous medium using an azo dye containing phenanthroimidazole
Subject Areas : آلودگی منابع آب
Zahra Zamiraei
1
,
Kurosh Rad Moghadam
2
1 - Department of Chemistry, University Campus, University of Guilan, Rasht, Iran
2 - Department of Chemistry, Faculty of Sciences, University of Guilan, Rasht, Iran
Keywords: Azo dyes, Phenanthroimidazole, Cyanide ion, Optical chemosensor, Environmental toxicity,
Abstract :
In this study, the synthesis and application of a novel azo dye containing a phenanthro[10,9-d] imidazole group as a chemosensor for cyanide ions (CN⁻) in aqueous media were investigated. Due to its high toxicity and detrimental effects on human health and natural ecosystems, cyanide requires rapid, sensitive, and selective detection methods. The synthesized dye exhibited high selectivity and sensitivity toward CN⁻ via an optical absorption mechanism accompanied by a distinct color change, enabling effective detection even in the presence of competing anions. Spectroscopic analysis revealed a detection limit of 5 × 10⁻⁶ M based on absorption spectral analysis, while the visual detection limit using test strips was found to be 2 × 10⁻⁵ M. A noticeable color transition from pale yellow to orange, along with a red shift in the UV-Vis spectrum, indicated the formation of a stable complex between the dye and the cyanide ion. To improve the practical applicability of this method, test strips were fabricated by immobilizing the synthesized dye, allowing for rapid and visual detection of CN⁻ in real samples (such as industrial wastewater and effluents) without the need for complex instrumentation. Owing to its simplicity, low cost, high sensitivity, and excellent selectivity, the proposed method shows great potential for environmental monitoring, industrial applications, and water quality assessment.
