Electrokinetic protein preconcentration using a simple glass/poly(dimethylsiloxane) microfluidic chip
Electrokinetic protein preconcentration using a simple glass/poly(dimethylsiloxane) microfluidic chip
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DOI：
10.1021/ac060031y
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发表时间：
2006-07-15
影响因子：
7.4
通讯作者：
Hasselbrink, Ernest F.
中科院分区：
文献类型：
--
作者：
Kim, Sun Min;Burns, Mark A.;Hasselbrink, Ernest F.
我们发现，蛋白质浓缩装置可以使用简单的单层制造工艺来构建。微流体半通道使用PDMS中的标准程序模制; PDMS层可逆地结合到玻璃基底，例如显微镜载玻片。微流体通道呈人字形，呈镜像取向，其顶点被设计成在彼此近似20 μ m的范围内通过，在通道之间形成薄壁部分。当在该薄壁部分上施加电场时，观察到带负电荷的蛋白质集中在其阳极侧。在30分钟内实现约10（3）-10（6）倍的蛋白质浓缩。通过将电场方向切换为与薄壁部分平行的方向，可以容易地实现两种不同浓缩蛋白质的后续分离。我们假设，由于弱的，可逆的键合方法，PDMS和玻璃之间形成纳米通道。该假设得到以下观察结果的支持：当PDMS和玻璃不可逆地结合时，直到施加非常高的电场并观察到PDMS的介电击穿才观察到该现象。因此，我们怀疑双电层重叠引起的离子排斥富集效应诱导了该纳米通道的阳离子选择性。这种简单的芯片上蛋白质预浓缩和分离装置可能是一个有用的组成部分，在实际上任何PDMS-on-glass微流体装置用于蛋白质测定。
We discovered that a protein concentration device can be constructed using a simple one-layer fabrication process. Microfluidic half-channels are molded using standard procedures in PDMS; the PDMS layer is reversibly bonded to a glass base such as a microscope slide. The microfluidic channels are chevron-shaped, in mirror image orientation, with their apexes designed to pass within similar to 20 mu m of each other, forming a thin-walled section between the channels. When an electric field is applied across this thin-walled section, negatively charged proteins are observed to concentrate on the anode side of it. About 10(3)-10(6)-fold protein concentration was achieved in 30 min. Subsequent separation of two different concentrated proteins is easily achieved by switching the direction of the electric field in the direction parallel to the thin-walled section. We hypothesize that a nanoscale channel forms between the PDMS and the glass due to the weak, reversible bonding method. This hypothesis is supported by the observation that, when the PDMS and glass are irreversibly bonded, this phenomenon is not observed until a very high E-field was applied and dielectric breakdown of the PDMS is observed. We therefore suspect that the ion exclusion-enrichment effect caused by electrical double layer overlapping induces cationic selectivity of this nanochannel. This simple on-chip protein preconcentration and separation device could be a useful component in practically any PDMS-on-glass microfluidic device used for protein assays.