Abstract
Carbon paste electrode (CPE) modified with porous copper based metal organic framework (Cu-MOF) nanocomposite is described for analysis of cyanide (CN−) for the first time. The electrochemical performance of the proposed electrode was investigated by differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The Cu-MOF nanocomposite was characterized using scanning electron microscope (SEM), N2-adsorption-desorption isotherms, powder X-ray powder diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Under optimal conditions of measurements, the anodic peak (Ipa) decreases linearly in the range of 1.87–25 μM with LOD of 0.60 μM (at S/N = 3). The Cu-MOF/CPE showed good selectivity towards CN− measurement with no significant interference in pH 7.0 using 0.25 M KCl to increase the medium conductivity and to stabilize the analyte and prevents its volatility. Moreover, the method was successfully applied for determination of CN− in different environmental water samples.
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•A new electrochemical sensor was proposed for analysis of cyanide (CN−) for the first time.•The electrochemical sensor is a porous copper metal organic framework (Cu-MOF) modified carbon paste electrode.•The mechanism of detection based on decreasing the peak currents of Cu-MOF by the target analyte CN−.•The sensor exhibits good sensitivity, stability, reproducibility, and sufficient selectivity towards CN−.•The proposed sensor was used to detect CN− in different water samples with satisfactory results.