Silver Doped Poly(L-valine) Modified Glassy Carbon Electrode for the Simultaneous Determination of Uric Acid, Ascorbic Acid and Dopamine

In this paper, a silver doped poly(L-valine) (Ag-PLV) modified glassy carbon electrode (GCE) was fabricated through electrochemical immobilization and was used to electrochemically detect uric acid (VA), dopamine (DA) and ascorbic acid (AA) by linear sweep voltammetry. In pH 4.0 PBS, at a scan rate of 100 mV/s, the modified electrode gave three separated oxidation peaks at 591 mV, 399 mV and 161 mV for VA, DA and AA, respectively. The peak potential differences were 238 mV and 192 mV. The electrochemical behaviors of them at the modified electrode were explored in detail with cyclic voltammetry. Under the optimum conditions, the linear ranges were 3.0 x 10(-7) to 1.0 x 10(-5) M for VA, 5.0 x 10(-7) to 1.0 x 10(-5) M for DA and 1.0 x 10(-5) to 1.0 x 10(-3) M for AA, respectively. The method was successfully applied for simultaneous determination of VA, DA and AA in human urine samples.