School of Pharmacy, Fudan University, Shanghai, P. R. China.
Electrophoresis. 2009 Oct;30(19):3419-26. doi: 10.1002/elps.200900019.
In this report, a novel carbon nanotube/poly(ethylene-co-vinyl acetate) (CNT/EVA) composite electrode was developed for the amperometric detection in CE. The composite electrode was fabricated by packing a mixture of CNTs and melted EVA in a piece of fused-silica capillary under heat. It was coupled with CE for the separation and detection of esculin and esculetin in Cortex Fraxini, a traditional Chinese medicine, to demonstrate its feasibility and performance. Esculin and esculetin have been well separated within 9 min in a 40 cm long capillary at a separation voltage of 12 kV using a 50 mM borate buffer (pH 9.2). The new CNT-based CE detector offered significantly lower detection potentials, yielded enhanced S/N characteristics, and exhibited high resistance to surface fouling and enhanced stability. It showed long-term stability and reproducibility with relative standard deviations of less than 5% for the peak current (n=15) and should also find a wide range of applications in other microfluidic analysis systems.
在本报告中，开发了一种新型的碳纳米管/聚乙烯-醋酸乙烯共聚物（CNT/EVA）复合电极，用于 CE 中的电流安培检测。该复合电极是通过在熔融的硅毛细管中填充 CNTs 和熔融的 EVA 的混合物，在加热下制备而成。将其与 CE 结合，用于分离和检测中药秦皮中的秦皮苷和秦皮素，以证明其可行性和性能。在 40cm 长的毛细管中，使用 50mM 硼酸盐缓冲液（pH9.2），在 12kV 的分离电压下，秦皮苷和秦皮素可在 9min 内得到很好的分离。新型基于 CNT 的 CE 检测器提供了更低的检测电位，产生了增强的 S/N 特性，并表现出对表面污染的高抵抗力和增强的稳定性。它具有长期稳定性和重现性，峰电流的相对标准偏差小于 5%（n=15），并且应该在其他微流控分析系统中得到广泛应用。
