尿酸和叶酸存在下改性碳纳米管糊电极上多巴胺电催化氧化MohammadMazloum-Ardakani,MahboobeAbolhasani,Bibi-FatemehMirjalili,MohammadAliSheikh-Mohseni,AfsanehDehghani-Firouzabadi,AlirezaKhoshroo简

Electrocatalysis of dopamine in the presence of uric acid and folic acid on modified carbon nanotube paste electrode

A chemically modified carbon paste electrode (CPE), consisting of 2,2''-[(1E)-(1,2-phenylenebis(azanylylidene)] bis(methanylylidene)]bis(benzene-1,4-diol) (PBD) and multiwalled carbon nanotubes (CNTs), was used to study the electrocatalytic oxidation of dopamine using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry (DPV). First, the electrochemical behavior of the modified electrode was investigated in buffer solution. Then the diffusion coefficient, electrocatalytic rate constant, and electron-transfer coefficient for dopamine oxidation at the surface of the PBD-modified CNT paste electrode were determined using electrochemical approaches. It was found that under optimum conditions (pH = 7.0), the oxidation of dopamine at the surface of such an electrode occurred at about 200 mV, lower than that of an unmodified CPE. DPV of dopamine at the modified electrode exhibited two linear dynamic ranges, with a detection limit of 1.0 μmol/L. Finally, DPV was used successfully for the simultaneous determination of dopamine, uric acid, and folic acid at the modified electrode, and detection limits of 1.0, 1.2, and 2.7 μmol/L were obtained for dopamine, uric acid, and folic acid, respectively. This method was also used for the determination of dopamine in a pharmaceutical preparation using the standard addition method.