Flow-through sampling for electrophoresis-based microfluidic chips using hydrodynamic pumping
Flow-through sampling for electrophoresis-based microfluidic chips using hydrodynamic pumping
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DOI：
10.1016/s0021-9673(01)01326-7
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发表时间：
2001-12-07
影响因子：
4.1
通讯作者：
Chen, SH
中科院分区：
文献类型：
--
作者：
Lin, YH;Lee, GB;Chen, SH
这项工作提出了一种新的电泳微芯片设计，它是能够直接耦合与流通分析器不间断采样。在该装置中，3 mm宽的采样通道（SC）被蚀刻在石英基板上，以创建样品入口和出口，并且75 μ m宽的电泳通道也被制造在同一基板上。使用压力驱动样品流通过外管进入SC，然后将流分流到出口和电泳通道中。向电泳通道施加门控电压以控制后续分离的样品加载并抑制样品泄漏。抑制样品泄漏所需的最小门控电压依赖于缓冲溶液，并随流体动力学流速的增加而增加。将含有罗丹明B和Cy3的荧光染料混合物通过在线进样阀以连续或离散模式引入样品流中，然后在微芯片上使用激光诱导荧光进行分离和检测。对于两种模式，连续进样的迁移时间和峰强度的相对标准偏差分别测定为低于0.6%和8%。由于SC保持浮动，外部采样设备不需要电气连接。因此，这种基于微芯片的微芯片可以直接与任何压力驱动的流量分析仪耦合，而无需硬件修改。据我们所知，这是目前报道的电泳微芯片设计不可能的。(C)2001 Elsevier Science B.V.保留所有权利。
This work presents a novel electrophoretic microchip design which is capable of directly coupling with flow-through analyzers for uninterrupted sampling. In this device, a 3 mm wide sampling channel (SC) was etched on quartz substrate to create the sample inlet and outlet and the 75 mum wide electrophoretic channels were also fabricated on the same substrate. Pressure was used to drive the sample flow through the external tube into the SC and the flow was then split into outlet and electrophoretic channels. A gating voltage was applied to the electrophoretic channel to control the sample loading for subsequent separations and inhibit the sample leakage. The minimum gating voltage required to inhibit the sample leakage depended on the solution buffer and increased with the hydrodynamic flow-rate. A fluorescent dye mixture containing Rhodamine B and Cy3 was introduced into the sample stream at either a continuous or discrete mode via an on-line injection valve and then separated and detected on the microchip using laser-induced fluorescence. For both modes, the relative standard deviation of migration time and peak intensity for consecutive injections was determined to be below 0.6 and 8%, respectively. Because the SC was kept floating, the external sampling equipment requires no electric connection. Therefore, such an electrophoresis-based microchip can be directly coupled with any pressure-driven flow analyzers without hardware modifications. To our best knowledge, this is something currently impossible for reported electrophoretic microchip designs. (C) 2001 Elsevier Science B.V. All rights reserved.