Magnetic Core- shell Fe3O4@SiO2/Graphene Nanocomposite Modified Carbon Paste Electrode for Voltammetric Determination of Ascorbic Acid in the presence of L-Cysteine

An ionic liquid– magnetic core–shell Fe3O4@SiO2/graphene nanocomposite modified carbon paste electrode (ILFSGCPE) was used as a fast and sensitive tool for the investigation of the electrochemical oxidation of ascorbic acid using voltammetry. This modified electrode has been fabricated using hydrophilic ionic liquid (n-hexyl-3methylimidazolium hexafluoro phosphate) as a binder. The modified electrode offers a considerable improvement in voltammetric sensitivity toward ascorbic acid, compared to the bare electrode. Using differential pulse voltammetry (DPV), the electrocatalytic oxidation peak current of ascorbic acid shows a linear calibration curve in the range of 1.0×10-6 to 9.0×10−4 M ascorbic acid. The limit of detection was equal to 2.3×10-7 M. The electrode was also employed to study the electrochemical oxidation of ascorbic acid in the presence of Lcysteine.