Direct Electrodeposition to Fabricate Vertically-Oriented Graphene Nanosheets Modified Electrode and its Application for Determination of Levodopa in the Presence of Uric Acid and Ascorbic Acid

The electrodeposition of reduced graphene oxide (rGO) film with preferred vertical orientation was fabricated on a glassy carbon electrode by using pulse potential method in a graphene oxide solution. The rGO film was applied in developing a high-sensitive electrochemical sensor for detection of levodopa (L-dopa). The new electrochemical sensor displayed a significant response to L-dopa because of its excellent electric conductivity and large specific surface area. Moreover, the determination of L-dopa on this modified electrode was not interfered by the coexistence of ascorbic acid (AA) and uric acid (UA). Under the selective conditions, the modified electrode showed a linear voltammetric response to L-dopa within a certain concentration ranging from 5 . 0 × 1 0 − 7 − 1 . 5 × 1 0 − 4 mol L − 1 , with the detection limit of 1 . 0 × 1 0 − 7 mol L − 1 . Besides, the modified electrode also exhibited an excellent selectivity, stability, reproducibility and repeatability.