Document Type : Research Paper
Faculty of Science, Chemistry Department, South Valley University, Qena, 83523, Egypt
A selective and sensitive voltammetric sensor was constructed using a Poly(methyl orange)/glassy carbon electrode (PMO/GCE). The PMO/GCE sensor was applied to investigate the electrochemical behavior of ascorbic acid (AA) and vitamin B2 (VB2) in PBS buffer solution. The sensor was applied for individual and simultaneous determination of AA and VB2using cyclic and differential pulse voltammetry (DPV) techniques. Different experimental parameters including scan rate(25-500 mV/s), pH (4-8 for AA and 3-10 for VB2) and analyte concentration (10-40 µM for AA and 4-85 µM for VB2) have been studied and optimized. High electrocatalytic activities for AA and VB2 oxidation were achieved at pH 7.0 and 6.0, respectively. In addition, results denoted that the oxidation process of AA and VB2 was under diffusion control. The respective detection limits, quantitation limits and linear ranges were 0.575, 1.916 and 10-40 μM for AA and 0.922, 3.073 and 5-85 μM for VB2under the optimized DPV conditions. Peak separation of AA from VB2was 660 mV which is enough to determine these vitamins simultaneously. The fabricated sensor has been applied successfully for estimation of AA and VB2 in real samples with good selectivity, stability and reproducibility.