Determination of α-tocopherol using positive scan polarization reverse catalytic voltammetry

Silver oxide nanoparticles were formed at the surface of a silver electrode with anodic polarization, then the carboxyl graphene-nanosheets were electrodeposited on the silver oxide with cyclic potential scanning, and the graphene/silver oxide/silver electrode was successfully prepared and applied in detection of α-tocopherol in the alkaline medium. The electrochemical behavior and the electrocatalytic activity of the modified electrode were investigated using cyclic voltammetry. The α-tocopherol was detected by means of this modified electrode and the positive scan polarization reverse catalytic voltammetry. The experimental results demonstrate that the thus-prepared modified electrode is stable and has high sensitivity. Two linear relationships between the difference value peak current and the α-tocopherol concentration are obtained in the range of 0.02~0.32 μmol/L and 0.32~4.0 μmol/L respectively, with a limit of detection reaching 0.01 μmol/L.