Analysis of sunset yellow at poly(L-glutamic acid) modified carbon nanotube paste electrode

This study shows the development of an electrochemical sensor for the simultaneous analysis of Sunset Yellow (SSY) and Indigo Carmine (IC). These two dyes were analysed using an electrode modified from carbon-nanotube paste which was electrochemically polymerised using L-glutamic acid (P(L-GLA)/MOCNTE). Numerous characterization methods were used to evaluate both modified and bare carbon nanotube paste electrode (BCNTE), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive x-ray spectroscopy (EDX), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), differential pulse voltammetry (DPV), and also linear stripping voltammetry (LSV). Scan rate shows that the process was governed by both adsorption and diffusion. Additionally, parameters like study of pH and concentration variation were used to enhance the sensor's performance. The P(L-GLA)/MOCNTE showed superior electrochemical characteristics, with limit of detection (LOD) of 0.68µM and limit of quantification (LOQ) of 2.21µM. P(L-GLA)/MOCNTE shows good performance in real samples making it capable for practical applications.