A sensitive detecting and analyzing of indigo carmine at ZnO nanoparticle modified carbon paste electrode: a voltammetric study
Puneeth, B.E. Kumara Swamy, L.S. Manjunatha
Abstract
Aim: Here, in this study we are synthesing Zinc oxide nanoparticles (ZnO NPs) via the co-precipitation method, and the various properties of the prepared nanoparticles were investigated using X-ray diffraction (XRD), scanning electron microscopy (XRD), and energy dispersive spectroscopy (EDS). Methods: In this work, we have enhanced a sensitive carbon paste electrode for detecting Indigo Carmine (IC), a food dye using ZnO NPs. IC is widely used in food products and the textile industry but has toxic effects on the environment. The ZnO NPs-based carbon paste electrode shows excellent sensitivity compared to the bare carbon paste electrode (BCPE) for IC. Studies on pH, different scan rates, stability, and simultaneous determination (for ascorbic acid (AA) and IC, Dopamine (DA) and IC) were conducted using cyclic voltammetry and the concentration, interference studies were performed using differential pulse voltammetry. Results: The electrochemical process for IC at the ZnO-modified carbon paste electrode (ZnO-MCPE) was found to be adsorption-controlled, with protons and electrons being equally transferred during the reaction. The prepared electrode was used to simultaneously determine IC in the presence of AA and DA in respective binary mixtures. The interference study shows that the fabricated ZnO-incorporated electrode can successfully measure IC in the presence of AA and DA at the given concentrations, and vice versa. The limit of detection (LOD) and quantification (LOQ) for IC at the ZnO-MCPE are 0.352 and 1.176 µM, respectively, with 90% stability over 15 cycles. Conclusion: The prepared modified electrode shows excellent electro-catalytic activity towards detection of organic textile dyes.