Electrochemical investigation of environmental pollutant, azo dye (calmagite) using modified zinc oxide carbon paste electrode

The Zinc oxide nanoparticle was synthesised by the co-precipitation method and obtained nanoparticle was characterised by X-ray diffraction (XRD), Scanning electron microscope (SEM), and Energy dispersive spectroscopy (EDS) techniques. For the detection of pollutant like calmagite, the electrochemical sensor is developed and key parameters like pH, scan rate, concentration, simultaneous, and interference, in 0.2 M phosphate buffer solution (pH 7.0) at the scan rate 50 mV/s was studied for the zinc oxide modified carbon paste electrode (ZnO/MCPE) using the cyclic voltammetric method. The modified carbon paste electrode exhibits a good electrocatalytic response and good sensitivity towards the detection of the analyte. A very low limit of detection (LOD), the limit of quantification (LOQ) were found i.e. 0.3834 × 10−8 M and 1.2783 × 10−8 M respectively and along with the linear range 0.1 to 0.6 × 10−4 M concentration. A good recovery rate is obtained from real sample analysis at modified carbon paste electrode. Hence ZnO/MCPE can be used as a sensor for the determination of calmagite individually and simultaneously.