Coulometric detection of components in liquid plugs by microfabricated flow channel and electrode structures.
Coulometric detection of components in liquid plugs by microfabricated flow channel and electrode structures.
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DOI：
10.1021/ac102289a
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发表时间：
2010-09
影响因子：
7.4
通讯作者：
F. Sassa;H. Laghzali;J. Fukuda;H. Suzuki
中科院分区：
文献类型：
--
作者：
F. Sassa;H. Laghzali;J. Fukuda;H. Suzuki
库仑计量法已被证明是在流动通道中测定纳升尺度的液体塞中分析物的有效方法。将辅助流道的菱形结构的塞子放置在薄膜三电极系统上，以过氧化氢为模型分析物。在固定电位下，电流迅速衰减，特别是在浅水流道中，因此很难进行可重复性的安培检测。另一方面，库仑测量过程中电荷的增加也促进了测量。以铂条阵列为工作电极的狭窄流动通道结构有效地消耗了分析物，提高了灵敏度，降低了检测下限。与相同面积的单个短工作电极相比，流道高度和条间距离的最佳组合的灵敏度提高了4倍。随着产生电流的增加，同时将本底保持在低水平，使用相同面积的工作电极，检测下限从1.3nM降至410nM。此外，还介绍了含有L谷氨酸和L谷氨酸氧化酶的溶液的处理和L谷氨酸的检测。
Coulometry has been demonstrated to be effective for determining the analyte in a liquid plug on the nanoliter-scale confined in a flow channel. A plug prepared in a rhombus structure of an auxiliary flow channel was placed on a thin-film three-electrode system, and hydrogen peroxide was detected as a model analyte. Under a fixed potential, the current decayed rapidly, particularly in shallow flow channels, thus making reproducible amperometric detection difficult. On the other hand, the increasing charge during coulometry facilitated the measurements. A constricted flow channel structure with an array of platinum strips for the working electrode was effective at efficiently consuming the analyte to improve the sensitivity and lower the detection limit. Compared to the case of a single short working electrode with the same area, a 4-fold increase in sensitivity was observed for the best combination of flow channel height and interstrip distance. With an increase in the generated current while maintaining the background at a low level, the detection limit was lowered from 1.3 μM to 410 nM using working electrodes with the same area. Furthermore, the processing of solutions containing L-glutamate or L-glutamate oxidase and the detection of L-glutamate were demonstrated.