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-3-methylimidazolium 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 l-cysteine. © 2016 by cee.