In-channel dual-electrode amperometric detection in electrophoretic chips with a palladium film decoupler
In-channel dual-electrode amperometric detection in electrophoretic chips with a palladium film decoupler
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DOI：
10.1016/j.chroma.2003.09.053
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发表时间：
2004-01-09
影响因子：
4.1
通讯作者：
Ko, FH
中科院分区：
文献类型：
--
作者：
Lai, CCJ;Chen, CH;Ko, FH
将钯膜电极和串联双电极集成在一起的电泳芯片被证明是实用的（200- 800 V/cm），用于常规安培检测。在流体系统中，平行相对双电极检测的安培增强是由于电极之间的分析物的氧化还原循环。然而，我们发现，通过从单电极模式切换到双串联模式，儿茶酚胺的氧化电流显著增强（1.9-3.8倍）。这一新的发现是出乎意料的，因为微流体系统的单向流动特性应该消除分析物在上游和下游电极之间来回物理迁移的可能性。我们将增强归因于通过将流动冲击到下游电极的边缘上而产生的湍流。DA和CA的线性范围、灵敏度、检测限（S/N = 3）和理论塔板数分别为0.5-50 μ M。47 pA/muM，0.25 muM，7000 m（-1）和1.0-100 muM，28 pA/muM，0.49 muM，15 000 m（-1）。(C)2003 Elsevier B. V.保留所有权利。
An electrophoretic microchip integrated with a Pd-film decoupler and a series-dual electrode was proven practical (200-800V/cm) for routine amperometric detection. In fluidic systems, amperometric enhancement of parallel-opposed dual-electrode detection is due to redox cycling of analytes between the electrodes. We, however, found that the oxidation current of catecholamines was enhanced significantly (1.9-3.8 folds) by switching from the single electrode mode to dual-series mode. This novel finding was unexpected because the unidirectional flow characteristic of the microfluidic system should eliminate the possibility for analytes physically migrating back and forth between the upstream and downstream electrodes. We attribute the enhancement to turbulence generated by impinging of the flow onto the edge of the downstream electrode. The linear range, sensitivity, limit of detection (S/N = 3) and number of theoretical plates for DA and CA are, respectively, 0.5-50 muM. 47 pA/muM, 0.25 muM, 7000 m(-1), and 1.0-100 muM, 28 pA/muM, 0.49 muM, 15 000 m(-1). (C) 2003 Elsevier B.V. All rights reserved.