Voltammetric Determination of Ascorbic Acid and Dopamine Simultaneously at a Single Crystal Au(111) Electrode

Authors : Zekerya DURSUN, Levent PELİT, İsao TANIGUCHI

Pages : 223-231

View : 17 | Download : 5

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A single-crystal Auinsert ignore into journalissuearticles values(111); electrode was used for the simultaneous determination of dopamine insert ignore into journalissuearticles values(DA); and ascorbic acid insert ignore into journalissuearticles values(AA); in a phosphate buffer solution at pH 6.9. The single-crystal Auinsert ignore into journalissuearticles values(111); electrode displayed excellent electrocatalytic activity for DA and AA oxidation in comparison to a Au disk electrode. Although the anodic peaks of both reagents overlapped on the Au disk electrode, the anodic peak potentials of DA and AA in their mixture were well separated since the peak potential of AA was shifted to more negative values by cyclic and differential pulse voltammetry. The oxidation peak current increased linearly with the concentration of DA in the range of 5 \times 10-6-5 \times 10-4 mol/L in the presence of 5 \times 10-4 mol/L AA. The detection limit of DA was 5 \times 10-7 mol/L. The peak current also linearly increased with increasing AA concentration in the presence of 5 \times 10-4 mol/L DA in the range of 1 \times 10-6-5 \times 10-4 mol/L. The detection limit of AA was 5 \times 10-8 mol/L insert ignore into journalissuearticles values(s/n = 3);. The single-crystal Auinsert ignore into journalissuearticles values(111); electrode showed excellent electrocatalytic activity to both AA and DA, probably because hydrogen flame treatment made the single-crystal electrode surface a well-defined atomic structure.
Keywords : Au 111, single crystal electrode, dopamine, ascorbic acid, voltammetry, simultaneous determination