Vitamin C analysis in food and pharmaceutical samples using a nanostructure electrochemical sensor

Ascorbic acid (vitamin C, AA) plays an important role in human health. In one of its functions, it assists in the absorption of iron by promoting iron reduction to the ferrous state, which isnecessary for the formation of collagen. Moreover, diets poor in AA lead to increased susceptibility to many kinds of infections and slow down the healing of wounds and fractures [1]. The direct electrochemistry of AA on a modified carbon paste electrode (CPE) wasdescribed. The electrode was modified with Zinc oxide (ZnO) nanoparticles and 1,3- dipropylimidazolium bromide as a binder. The oxidation peak potential of AA at the surface ofthe ionic liquid ZnO appeared at 550 mV, which was about 80 mV lower than the oxidation peak potential at the surface of the traditional carbon CPE under a similar condition. The linear response range and detection limit were found to be 0.1–400 μmol L−1 and 0.05 μmol L−1,respectively. Other physiological species did not interfere in the determination of AA at the surface of the proposed sensor in the optimum condition. The proposed sensor was successfully applied for the determination of AA in real samples.

Keywords:

Ascorbic acid , ZnO nanoparticles , Modified electrode