聚3,4-乙撑二氧噻吩/金复合电极的制备及其在多巴胺检测中的应用

Preparation of poly( 3,4-ethylenedioxythiophene)/gold composite electrode and its application in dopamine detection

在水溶液中，以对甲苯磺酸钠为支持电解质，在氧化铟锡导电玻璃上，采用电化学恒电位极化法制备聚3，4-乙撑二氧噻吩（ PEDOT）修饰电极。通过电化学循环伏安法，在PEDOT电极上沉积金纳米颗粒（ Au NPs），制得PEDOT/Au复合修饰电极，用于多巴胺（ DA）的电化学检测。考察了PEDOT/Au复合修饰电极中Au NPs的沉积量对DA电化学检测响应的影响，同时研究了在干扰物质抗坏血酸（ AA）和尿酸（ UA）存在时，PEDOT/Au复合修饰电极对DA的检测。结果表明，在中性pH溶液中，利用PEDOT/Au复合修饰电极，采用差分脉冲伏安法检测DA的线性范围为5×10-6～1×10-4 mol/L，最低检测限可达1×10-8 mol/L，且能有效排除AA和UA的干扰，实现三者的同时检测。

The poly（ 3,4-ethylenedioxythiophene）（ PEDOT） electrode was synthesized on indium tin oxide（ ITO） glass substrate via electrochemical polarization under a constant bias in sodium p-toluenesulfonate（ Ts ONa） aqueous solution. PEDOT / Au composite electrode was fabricated through cyclic voltammetry method and then was used for electrochemical detection of dopamine（ DA）. The influence of the loading amount of Au NPs in the PEDOT / Au composite electrode on DA detection was discussed. Furthermore,the electrochemical detection of DA was also studied using the PEDOT / Au electrode in the presence of ascorbic acid（ AA） and uric acid（ UA）. The result showed that in neutral aqueous solution,the DA concentration could be determined in a linear range of 5 × 10- 6～ 1 × 10- 4mol / L,and the detection limit of DA was found to be 1 × 10- 8mol / L. The results indicated that the PEDOT / Au composite film showed high sensitivity and selectivity for DA electrochemical detection even in the presence of interferents like AA and UA.