中文摘要：

多巴胺（DA）是哺乳动物的一种非常重要的神经递质，人们制备了各种修饰电极用于DA的测定.近年来，将DNA修饰电极用于电催化多巴胺的研究已有报道，如Lin等研制了DNA纳米网络碳纤维电极，Hu等制备了ssDNA-SWNTs（单壁碳纳米管）修饰电极．本文通过电化学聚合法在碳糊电极上共聚制备了聚邻氨基酚／Ni^2＋膜（Ni^2＋／P-OAP／CPE），研究了膜的伏安特性，并制成dsDNA修饰电极，通过电化学和紫外光谱法进行表征．将dsDNA／Ni^2＋／P-OAP／CPE电极应用于多巴胺的电催化氧化，同时将该方法用于盐酸多巴胺针剂的测定，亦获得了满意的结果．

英文摘要：

The Ni^2＋/poly （o-aminophenol） electropolymerization was carried out by a continuous cyclic voltammetric scanning at a carbon paste electrode in a mixture of 0. 02 mol/L o-aminophenol, 0. 3 mol/L NiSO4 and 0. 6 mol/L HCIO4. dsDNA was linked to the conducting polymer via three-dimensional structure of polymer film and electrostatic attraction between the negatively charged phosphate backbone of DNA and Ni^2＋ ion. The results were testified by the electrochemical methods by using Co（phen）3^2＋ as an electrochemical indicator. The currents of redox peaks of Co（phen）3^2＋ increased after immobilizing dsDNA. The conditions for the preparation of Ni^2＋/P-OAP/CPE and DNA immobilization were optimized. The vohammetric behavior of dopa- mine was investigated at the modified electrode. It was found that the modified electrode exhibited a highly electrocatalytic activity toward dopamine oxidation. Differential pulse vohammetry was used for determination of dopamine in pH 5. 1 phosphate buffer solution. A linear response of the peak current versus the concentration was found in the range from 5.0×10^-6 to 2. 0×10^-4mol/L with 1. 0× 10^-2mol/L AA（ascorbic acid） coexisting. The presence of a high concentration of AA did not interfere with the determination. The proposed method exhibits a good recovery and reproducibility.