Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Dindigul, India.
Talanta. 2010 Mar 15;80(5):1686-91. doi: 10.1016/j.talanta.2009.10.007. Epub 2009 Oct 12.
This paper describes the simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA) and xanthine (XN) using an ultrathin electropolymerized film of 2-amino-1,3,4-thiadiazole (p-ATD) modified glassy carbon (GC) electrode in 0.20 M phosphate buffer solution (pH 5.0). Bare GC electrode failed to resolve the voltammetric signals of AA, DA, UA and XN in a mixture. On the other hand, the p-ATD modified electrode separated the voltammetric signals of AA, DA, UA and XN with potential differences of 110, 152 and 392 mV between AA-DA, DA-UA and UA-XN, respectively and also enhanced their oxidation peak currents. The modified electrode could sense 5 microM DA and 10 microM each UA and XN even in the presence of 200 microM AA. The oxidation currents were increased from 30 to 300 microM for AA, 5 to 50 microM for DA and 10 to 100 microM for each UA and XN, and the lowest detection limit was found to be 2.01, 0.33, 0.19 and 0.59 microM for AA, DA, UA and XN, respectively (S/N=3). The practical application of the present modified electrode was demonstrated by the determination of AA, UA and XN in human urine samples.
本文描述了使用 2-氨基-1,3,4-噻二唑（p-ATD）修饰的玻碳电极在 0.20 M 磷酸盐缓冲溶液（pH 5.0）中同时测定抗坏血酸（AA）、多巴胺（DA）、尿酸（UA）和黄嘌呤（XN）的方法。裸 GC 电极无法分辨混合物中 AA、DA、UA 和 XN 的伏安信号。另一方面，p-ATD 修饰电极将 AA、DA、UA 和 XN 的伏安信号分开，AA-DA、DA-UA 和 UA-XN 的电位差分别为 110、152 和 392 mV，同时还增强了它们的氧化峰电流。即使存在 200 μM 的 AA，修饰电极也可以检测到 5 μM 的 DA 和 10 μM 的每种 UA 和 XN。AA 的氧化电流从 30 到 300 μM 增加，DA 的氧化电流从 5 到 50 μM 增加，每种 UA 和 XN 的氧化电流从 10 到 100 μM 增加，最低检测限分别为 2.01、0.33、0.19 和 0.59 μM（S/N=3）。通过测定人尿样中的 AA、UA 和 XN，证明了本修饰电极的实际应用。
