多巴胺在聚L-天冬氨酸修饰电极上的催化氧化及测定

The Electrocatalytic Oxidation and Determination of Dopamine at Poly(L-Aspartic acid) Modified Electrode

研究了聚L_天冬氨酸修饰电极的制备及其电化学性质。实验表明 ,该修饰电极对神经递质多巴胺的电化学氧化有显著的催化作用 ,使电极反应过程的可逆性变好 ,峰电流明显增大。采用差示脉冲伏安法对多巴胺进行定量分析 ,线性范围为 1 0× 10 - 7～ 1 0× 10 - 4 mol L ,检出限为 5 0× 10 - 8mol L。该聚合物修饰电极具有良好的选择性 ,能有效地排除抗坏血酸对测定的影响 ,用于合成样品分析 ,结果令人满意。

The preparation and the electrochemical characteristics of poly(L-aspartic acid) modified electrode have been investigated. The experimental results show that the polymer modified electrode has strong catalytic effect towards the electrochemical oxidation of dopamine (DA). The linearity of DA in the range of 1.0×10 -7～1.0×10 -4 mol/L with detection limit of 1.0×10 -8 mol/L and the correlation coefficient of 0.998 9 are obtained from differential pulse voltammetry (DPV) using the troditional three-electrode system. The detection is free from the interference of some biological substances such as ascorbic acid, nitrite and L-arginine. A satisfactory determination result of DA in injection is obtained by this method.