Electrochemical Sensing of Environmental Pollutant Nigrosine Dye Using Poly-Aspartic Acid by Modified Carbon Paste Electrode

The present study aimed to design an electrochemical electrode for the analysis of nigrosine in 0.2 M of phosphate buffer saline by applying a modified carbon paste electrode. A simple and rapid method for fabricating a poly-aspartic acid-modified carbon paste electrode (PAAMCPE) was employed using cyclic voltammetry. Electrochemical impedance spectroscopy, cyclic voltammerty, and linear sweep voltammetry were applied to evaluate the efficiency of the fabricated electrode to detect nigrosine. The impact of nigrosine concentration variation on the oxidation peak response was studied using cyclic voltammetry and linear sweep voltammetry in the linear range of 0.2-8.0 mu M, with a limit of detection of 0.504 mu M and 0.292 mu M, respectively. Scanning electron microscopy was used to analyze the surface characteristics of the electrodes. Moreover, PAAMCPE demonstrates excellent sensitivity and selectivity in detecting nigrosine, even in the presence of other interfering substances. The developed electrode exhibited good selectivity for nigrosine in the presence of fast sulphon black F. The analysis of real sample was successfully conducted using the developed sensor.