聚吡咯／多壁碳纳米管修饰电极对多巴胺的测定  

Determination of dopamine by polypyrrole/multi-walled carbon nanotube modified electrode

作　　者：马曾燕[1] 李将渊[1] 向伟[1] 

机构地区：[1]化学应用与污染控制技术四川省重点实验室,西华师范大学化学化工学院,四川南充637002

出　　处：《化学研究与应用》2008年第12期1570-1574,共5页Chemical Research and Application

摘　　要：制备了聚吡咯／多壁碳纳米管（PPy／MWNT）复合膜修饰电极。研究了神经递质多巴胺（DA）在该修饰电极上的电化学行为。实验表明，PPy／MWNT复合膜修饰电极对DA的电催化作用优于PPy修饰电极。在pH＝4．10的0．2mol／L醋酸-醋酸钠缓冲溶液中，DA在该修饰电极上的CV曲线于0．31V和0．28V处出现一对灵敏的氧化还原峰，峰电位差△Ep比裸玻碳电极降低58mV，比PPy修饰电极降低28mV，峰电流显著增加。氧化峰电流ipa与DA浓度在1．0×10^-4 -7．8×10^-8 mol／L范围内呈良好的线性关系，线性回归方程为ip（μA）：0．2512＋1．2300C（×10^-5 mol／L），相关系数r=0．9992，检出限为3．9×10^-8 mol／L。常见物质对DA的检测无干扰，DA注射液样品检测回收率为94％-104％。A polypyrrole/muhi-wall carbon nanotube composite （PPy/MWNT）modified electrode was prepared, and the electrochemical behavior of dopamine（DA） on the PPy/MWNT modified electrode has been studied. According to the experiment, the PPy/MWNT modified electrode has stronger electrocatalytic effect on the oxidation of DA than polypyrrole （PPy）modified electrode does. In pH = 4. 10 HAc-NaAc buffer solution, one sensitive pair of redox peaks with Epa = 0. 31 V, Epa = 0.28V （vs. SCE） is obtained on the PPy/MWNT modified electrode. The difference of peak potentials（ AEp ）was 58mV lower than which on bare glassy carbon electrode, and about 28mV lower than which on PPy modified electrode. Meanwhile, the peak current was markedly increased. The oxidation peak current（ipa） increased linearly with the concentrations of DA in the range of 1.0×10^-4 -7.8×10^-8 mol/L. The linear regression equation is ip （μA） = 0. 2512 ＋ 1. 2300C（× 10^-5 tool/L）, with the correlation coefficient of 0. 9992, and the detection limit of 3.9 × 10^-4 mol/L. Normal substances didn＇t affect the determination of DA. The modified electrode applied to assess the contents of DA in dopamine hydrochloride injection could be recovered 94% -- 104%.

关 键 词：吡咯 多壁碳纳米管 多巴胺 修饰电极 

分 类 号：O646.5[理学—物理化学]