Electrochemical immunoassay on a microfluidic device with sequential injection and flushing functions
Electrochemical immunoassay on a microfluidic device with sequential injection and flushing functions
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DOI：
10.1016/j.bios.2007.02.010
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发表时间：
2007-06-15
影响因子：
12.6
通讯作者：
Suzuki, Hiroaki
中科院分区：
文献类型：
--
作者：
Nashida, Norihiro;Satoh, Wataru;Suzuki, Hiroaki
一个集成的微流控装置与注射，冲洗，和传感功能，实现了使用阀，直接电润湿的基础上操作。该装置由两个基板组成：具有驱动和传感电极的玻璃基板和聚（二甲基硅氧烷）（PDMS）基板。利用溶液在干膜光致抗蚀剂层形成的亲水性流动通道中的自发运动实现微流体传输。溶液的注入和冲洗由起阀门作用的金工作电极控制。阀形成在通道中或形成在玻璃基板中的通孔中。为了证明该系统对免疫测定的适用性，进行固定化抗原的检测作为夹心免疫测定的部分模拟。使用等离子体聚合膜（PPF）将人甲胎蛋白（AFP）或抗人AFP抗体固定在室中的铂工作电极上。通过向注射阀施加电势，将必要的溶液通过通道一个接一个地注射到芯片中心的反应室中，并孵育合理的时间段。然后通过冲洗阀冲洗溶液，并将其吸收在置于装置下方的滤纸中。与葡萄糖氧化酶（GOD）标记的相应抗体孵育后，进行电化学检测。在这两种情况下，获得的电流取决于固定化抗原的量。标准曲线呈S形，检出限为0.1ng。开发的微流控系统可能成为下一代微量免疫测定的基本组成部分。(c)2007 Elsevier B.V.保留所有权利。
An integrated microfluidic device with injecting, flushing, and sensing functions was realized using valves that operate based on direct electrowetting. The device consisted of two substrates: a glass substrate with driving and sensing electrodes and a poly(dimethylsiloxane) (PDMS) substrate. Microfluidic transport was achieved using the spontaneous movement of solutions in hydrophilic flow channels formed with a dry-film photoresist layer. The injection and flushing of solutions were controlled by gold working electrodes, which functioned as valves. The valves were formed either in the channels or in a through-hole in the glass substrate. To demonstrate the system's applicability to an immunoassay, the detection of immobilized antigens was performed as a partial simulation of a sandwich immunoassay. Human alpha-fetoprotein (AFP) or an anti-human AFP antibody was immobilized on a platinum working electrode in the chamber using a plasma-polymerized film (PPF). By applying a potential to the injection valves, necessary solutions were injected one by one through the channels into a reaction chamber at the center of the chip and incubated for reasonable periods of time. The solutions were then flushed through the flushing valve and absorbed in a filter paper placed under the device. After incubation with the corresponding antibodies labeled with glucose oxidase (GOD), electrochemical detection was conducted. In both cases, the obtained current depended on the amount of immobilized antigen. The calibration curves were sigmoidal, and the detection limit was 0.1 ng. The developed microfluidic system could potentially be a fundamental component for a micro immunoassay of the next generation. (c) 2007 Elsevier B.V. All rights reserved.