On-chip microfluidic transport and mixing using electrowetting and incorporation of sensing functions
On-chip microfluidic transport and mixing using electrowetting and incorporation of sensing functions
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DOI：
10.1021/ac050821s
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发表时间：
2005-11-01
影响因子：
7.4
通讯作者：
Suzuki, H
中科院分区：
文献类型：
--
作者：
Satoh, W;Hosono, H;Suzuki, H
开发了一种集成系统，该系统在单个芯片上执行微流体传输、混合和传感。微流体传输的操作原理是基于电润湿。将待输送的溶液限制在一排金工作电极和突出的聚（二甲基硅氧烷）（PDMS）结构之间的空间中。当负电位施加到其中一个金工作电极时，它变得亲水，并且溶液通过流动通道输送。通过逐一接通必要的电极，溶液可以在流动通道的网络中以任何期望的方向输送。此外，可以使用基于相同原理的混合电极来混合通过两个流动通道输送的两种溶液。为了证明芯片实验室的适用性，通过利用流动通道的开放结构来集成气隙氨电极。在pH调节后产生并通过气隙扩散的气态氨引起电解质层中的pH变化，该pH变化用氧化铱pH指示电极测量。90%的响应时间小于1分钟的氨的毫摩尔数量级。校准曲线在低至10 μ M时呈线性。氨传感系统也被应用于构建尿素和肌酐的生物传感系统。对于尿素和肌酸酐，在分析物浓度低至50 μ M的电位和对数之间观察到线性关系。开发的微流体系统可以成为未来系统的基本构建模块。
An integrated system was developed that performs microfluidic transport, mixing, and sensing on a single chip. The operation principle for the microfluidic transport was based on electrowetting. A solution to be transported was confined in a space between a row of gold working electrodes and a protruding poly(dimethylsiloxane) (PDMS) structure. When a negative potential was applied to one of the gold working electrodes, it became hydrophilic, and the solution was transported through the flow channel. The solution could be transported in any desired direction in a network of flow channels by switching on necessary electrodes one by one. Furthermore, two solutions transported through two flow channels could be mixed using a mixing electrode based on the same principle. To demonstrate the applicability of a lab-on-a-chip, an air gap ammonia electrode was integrated by taking advantage of the open structure of the flow channel. Gaseous ammonia that was produced after pH adjustment and diffused through an air gap caused a pH change in the electrolyte layer, which was measured with an iridium oxide pH indicator electrode. The 90% response time was less than 1 min for the millimolar order of ammonia. The calibration curve was linear down to 10 mu M. The ammonia-sensing system was also applied to construct biosensing systems for urea and creatinine. A linear relationship was observed between the potential and the logarithm of the concentration of the analytes down to 50 mu M for both urea and creatinine. The developed microfluidic system can be a basic building block for future systems.