JoVE Journal > Bioengineering
Summary
Abstract
Introduction
Protocol
Results
Discussion
Disclosures
Acknowledgements
Materials
References
Automatic Translation
Please note that all translations are automatically generated. Click here for the English version.
Bioengineering

并列的合并离子交换膜之间的离子浓差极化，以块极化区的传播

Published: February 23, 2017
doi:
10.3791/55313
, , , ,
1Center for BioMicrosystems,Korea Institute of Science and Technology, 2Department of Mechanical Engineering,Seoul National University, 3Department of Industrial Engineering,University of Illinois Urbana-Champaign

Summary

为一个新的离子浓度极化（ICP）平台的协议，可以停止ICP区的传播，不管操作条件进行说明。这一独特的平台能力，在于所使用的合并离子耗竭和充实，这是的ICP现象的两个极性。

Abstract

离子浓度极化（ICP）的现象是最普遍的方法来预浓缩低丰度的生物样品之一。该ICP诱导带电生物分子（即离子耗尽区）无创性区域和目标可以在此区域的边界上预浓缩。尽管高富集表演使用ICP，它是很难找到的非传播离子耗尽区中的操作条件。为了克服这个狭窄的操作窗口，我们最近开发了spatiotemporally固定富集的新平台。不像前述仅使用离子耗尽的方法，该平台还使用ICP（ 即，离子富集）的极性相反，停止离子耗尽区的传播。通过与耗尽区的富集区面临的两区合并在一起，并停止。在本文中，我们描述了详细的实验协议来建立这个spatiotemporally定义ICP platfORM和它们与常规设备的比较表征新平台的富集动态。定性离子浓度分布和电流 – 时间响应成功捕获合并的ICP和单机ICP之间的不同的动态。在与传统的一个可以仅〜5伏固定富集的位置，新的平台可以在操作条件的宽范围的特定位置产生一个目标冷凝插头：电压（0.5-100 V）中，离子强度（1-100毫摩尔）和pH（3.7-10.3）。

Introduction

离子浓度极化（ICP）是指在一个选择性渗透膜离子富集和离子耗尽期间发生，导致与离子浓度梯度1,2额外电位降的现象。该浓度梯度是线性的，并作为一个较高电压被施加（欧姆制度），直到在膜上的离子浓度变得更陡接近零（限制性制度）。在此扩散限制条件，梯度（和相应的离子通量）已被公知的最大化/饱和1。超出了这个常规理解，当电压（或电流）进一步增大时，一个overlimiting电流观察到的，与平坦耗尽区和非常尖锐的浓度梯度在区域边界1,3。平坦区具有一个非常低的离子浓度，但表面导电，电osmoti Ç渗流（EOF），和/或电渗透不稳定促进离子通量和诱导overlimiting电流的3，4，5。有趣的是，平耗尽区用作静电屏障，该滤波器滤除6，7，8，9和/或预浓缩目标10，11。由于存在不足量的离子以筛选带电粒子的表面电荷（对于满意的电中性），所述颗粒不能穿过该耗尽区，因此，在其边界排队。该非线性ICP效应是在不同类型的膜10，11，12，13的一个通用的现象，> 14和几何形状6，15，16，17，18，19，20，21;这就是为什么研究人员已经能够开发各类过滤6，7，8，9 富集采用非线性ICP 10，11台设备。

即使有这样的高度的灵活性和健壮性，它仍然是澄清的非线性ICP设备的操作条件的实用的挑战。比较方案的非线性区快速通过阳离子交换膜，这导致阴离子朝向阳极移动的位移去除阳离子。作为一个结果，平耗尽区传播快，这使人想起休克传播22。摩尼等。称这种动态的去离子（或耗竭）冲击23。到在指定的检测位置预浓缩的目标，防止离子耗尽区的扩展是必要的，例如，通过施加EOF或压力驱动流对区扩张24。 Zangle 等。 22澄清ICP传播的标准中的一维模型，它高度依赖于电泳迁移17，离子强度18，pH值25，等等。这表明，适当的操作条件将根据样品条件被改变。

在这里，我们提出详细的设计和实验协议，一个spatiotemp内预浓缩目标的新的ICP平台口服定义的26位。离子耗尽区的扩展是由离子富集区阻断，在一个指定的位置离开静止富集塞，不论工作时间，施加电压，离子强度和pH值。该详细视频协议是为了表明，以阳离子交换膜整合到微流体装置，并表明相比于以往的新ICP平台的富集性能的最简单的方法。

Protocol

1.阳离子交换膜制造集成微流控芯片 主人硅的制备 设计2种硅主人：一种用于图案化的阳离子交换树脂和其他建设有聚二甲基硅氧烷（PDMS）微通道。 注：几何细节将在步骤1.3.1和1.4.1的描述。 通过使用常规的光刻和深反应离子蚀刻27制造硅主人。 在真空罐30分钟Silanize的微图案硅主人与三氯硅烷（〜30μL）。 注意：三…

Representative Results

膜集成微流体预浓缩的概略的制造步骤示于图1。的制造的详细描述的协议中给出。在设计和spatiotemporally限定预浓缩26的设备中的图像进行了对比与那些常规的预浓缩11（ 图2）的。在spatiotemporally定义预浓缩的ICP现象的电流-电压-时间响应和荧光强度分布（ 图3-4）而言进行了研究。类似于用单膜预浓?…

Discussion

我们所描述的制造协议和spatiotemporally限定预浓缩的在一个范围内施加电压（0.5-100 V）离子强度（1-100毫米）的性能，和pH值（3.7-10.3），实现了10,000倍在10分钟内的染料与蛋白质的富集。像以前的ICP设备的富集性能变得更高更好的电压和更低的离子强度。我们可以考虑在此一附加参数在两个阳离子交换膜之间的距离。如果我们增加膜间的距离，电场施加相同的电压下降低，从而导致在预浓缩速度<sup…

Disclosures

The authors have nothing to disclose.

Acknowledgements

This work was supported by the internal fund of the Korea Institute of Science and Technology (2E26180) and by the Next Generation Biomedical Device Platform program, funded by the National Research Foundation of Korea (NRF-2015M3A9E202888).

Materials

Sylgard 184 Silicone Elastomer kit Dow Corning
Trichlorosilane Sigma Aldrich 175552 Highly toxic
Nafion perfluorinated resin, 20 wt% Sigma Aldrich 527122
Sodium chloride Sigma Aldrich 71394
Potassium chloride Sigma Aldrich 60121
Alexa Fluor 488 carboxylic acid, succinimidyl ester Invitrogen A20000
Isothiocyanate-conjugated albumin Sigma Aldrich A9771
Phosphate buffer saline, 1X Wengene LB004-02
Tween 20  Sigma Aldrich P1379
Epifluorescence microscope Olympus IX-71
Charged-coupled device camera Hamamtsu Co. ImageEM X2
Source measurement unit Keithley Instruments 2635A
Covance-MP Femto Science
DOWNLOAD MATERIALS LIST

References

  1. Probstein, R. F. . Physicochemical Hydrodynamics: An Introduction. , (2003).
  2. Strathmann, H. . Ion-Exchange Membrane Separation Processes. , (2004).
  3. Dydek, E. V., et al. Overlimiting Current in a Microchannel. Phys. Rev. Lett. 107 (11), 118301 (2011).
  4. Kwak, R., Pham, V. S., Lim, K. M., Han, J. Y. Shear flow of an electrically charged fluid by ion concentration polarization: scaling laws for electroconvective vortices. Phys. Rev. Lett. 110 (11), 114501 (2013).
  5. Rubinstein, I., Zaltzman, B. Electro-osmotically induced convection at a permselective membrane. Phys. Rev. E. 62 (2), 2238-2251 (2000).
  6. Kwak, R., Kim, S., Han, J. Continuous-flow biomolecule and cell concentrator by ion concentration polarization. Anal. Chem. 83 (19), 7348-7355 (2011).
  7. Jeon, H., Lee, H., Kang, K. H., Lim, G. Ion concentration polarization-based continuous separation device using electrical repulsion in the depletion region. Sci.Rep. 3, 3483 (2013).
  8. Kim, S. J., Ko, S. H., Kang, K. H., Han, J. Direct seawater desalination by ion concentration polarization. Nat. Nanotechnol. 5 (4), 297-301 (2010).
  9. MacDonald, B. D., Gong, M. M., Zhang, P., Sinton, D. Out-of-plane ion concentration polarizationfor scalable water desalination. Lab Chip. 14 (4), 681-685 (2014).
  10. Schoch, R. B., Han, J. Y., Renaud, P. Transport phenomena in nanofluidics. Rev.Mod. Phys. 80 (3), 839-883 (2008).
  11. Kim, S. J., Song, Y. A., Han, J. Nanofluidic concentration devices for biomolecules utilizing ion concentration polarization: theory, fabrication, and applications. Chem. Soc. Rev. 39 (3), 912-922 (2010).
  12. Mai, J. Y., Miller, H., Hatch, A. V. Spatiotemporal mapping of concentration polarization Induced pH changes at nanoconstrictions. ACS Nano. 6 (11), 10206-10215 (2012).
  13. Kim, B., et al. Tunable ionic transport for a triangular nanochannel in a polymeric nanofludic system. ACS Nano. 7 (1), 740-747 (2013).
  14. Mangano Syed, A., Mao, L., Han J, P., Song, Y. -. A. Creating sub-50 nm nanofluidic junctions in a PDMS microchip via self-assembly process of colloidal silica beads for electrokinetic concentration of biomolecules. Lab Chip. 14, 4455-4460 (2014).
  15. Wang, Y. C., Stevens, A. L., Han, J. Y. Million-fold preconcentration of proteins and peptides by nanofluidic filter. Anal. Chem. 77 (14), 4293-4299 (2005).
  16. Lee, J. H., Cosgrove, B. D., Lauffenburger, D. A., Han, J. Microfludic concentration-enhanced cellular kinase activity assay. J. Am. Chem. Soc. 131 (30), 10340-10341 (2009).
  17. Cheow, L. F., Han, J. Y. Continuous signal enhancement for sensitive aptamer affinity probe electrophoresis assay using electrokinetic concentration. Anal. Chem. 83 (18), 7086-7093 (2011).
  18. Ko, S. H., et al. Nanofluidic preconcentration device in a straight microchannel using ion concentration polarization. Lab Chip. 12 (21), 4472-4482 (2012).
  19. Gong, M. M., Nosrati, R., Gabriel, M. C. S., Zini, M., Sinton, D. Direct DNA analysis with paper-based ion concentration polarization. J. Am. Chem. Soc. 137 (43), 13913-13919 (2015).
  20. Hong, S., Kwak, R., Kim, W. Paper-based flow fractionation system applicable to preconcentration and field-flow separation. Anal. Chem. 88 (3), 1682-1687 (2016).
  21. Han, S. I., Hwang, K. S., Kwak, R., Lee, J. H. Microfluidic paper-based biomolecule preconcentrator based on ion concentration polarization. Lab Chip. 16, 2219-2227 (2016).
  22. Zangle, T. A., Mani, A., Santiago, J. G. Theory and experiments of concentration polarization and ion focusing at microchannel and nanochannel interfaces. Chem. Soc. Rev. 39 (3), 1014-1035 (2010).
  23. Mani, A., Bazant, M. Z. Deionization shocks in microstructures. Phys. Rev. E. 84, 061504 (2011).
  24. Slouka, Z., Senapati, S., Chang, H. C. Microfluidic systems with ion-selective membranes. Annu. Rev.Anal. Chem. 7, 317-335 (2014).
  25. Kirby, B. J., Hasselbrink, E. F. Zeta potential of microfluidic substrates: 1. Theory, experimental techniques, and effects on separations. Electrophoresis. 25 (2), 187-202 (2004).
  26. Kwak, R., Kang, J. Y., Kim, T. S. Spatiotemporally defining biomolecule preconcentration by merging ion concentration polarization. Anal. Chem. 88 (1), 988-996 (2016).
  27. Duffy, D. C., McDonald, J. C., Schueller, O. J. A., Whitesides, G. M. Rapid prototyping of microfluidic systems in poly(dimethylsiloxane). Anal. Chem. 70 (23), 4974-4984 (1998).
  28. Campbell, D. J., et al. Replication and compression of surface structures with polydimethylsiloxane elastomer. J. Chem. Educ. 76 (4), 537-541 (1999).
  29. Lee, J. H., Song, Y. A., Han, J. Y. Multiplexed proteomic sample preconcentration device using surface-patterned ion-selective membrane. Lab Chip. 8 (4), 596-601 (2008).
  30. Kwak, R., Guan, G., Peng, W. K., Han, J. Microscale electrodialysis: concentration profiling and vortex visualization. Desalination. 308, 138-146 (2013).
  31. Chambers, R. D., Santiago, J. G. Imaging and quantification of isotachophoresis zones using nonfocusing fluorescent tracers. Anal. Chem. 81, 3022-3028 (2009).
  32. Minerick, A. R., Ostafin, A. E., Chang, H. C. Electrokinetic transport of red blood cells in microcapillaries. Electrophoresis. 23 (14), 2165-2173 (2002).
  33. Phan, D. -. T., Shaegh, S. A. M., Yang, C., Nguyen, N. -. T. Sample concentration in a microfluidic paper-based analytical device using ion concentration polarization. Sens. Actuators B. 222, 735-740 (2016).
  34. Rubinstein, S. M. Direct observation of a nonequilibrium electro-osmotic instability. Phys. Rev. Lett. 101, 236101 (2008).
  35. Ouyang, W., et al. Microfluidic platform for assessment of therapeutic proteins using molecular charge modulation enhanced electrokinetic concentration assays. Anal. Chem. 88, 9669-9677 (2016).
  36. Cheow, L. F., Sarkar, A., Kolitz, S., Lauffenburger, D., Han, J. Detecting kinase activities from single cell lysate using concentration-enhanced mobility shift assay. Anal. Chem. 86, 7455-7462 (2014).
  37. Chen, C. -. H., et al. Enhancing protease activity assay in droplet-based microfluidics using a biomolecule concentrator. J. Am. Chem. Soc. 133, 10368-10371 (2011).
  38. Kwak, R., Pham, V. S., Kim, B., Lan, C., Han, J. Enhanced salt removal by unipolar ion conduction in ion concentration polarization desalination. Sci. Rep. 6, 25349 (2016).

Tags

Keywords: Ion Concentration PolarizationIon Exchange MembranesPreconcentrationBioagentsLow Abundance BiomoleculesSensor’s Limit Of DetectionICP ZonePhotolithographyPDMS MicrochannelCation-selective MembraneTrichlorosilaneSilicone ElastomerCation Exchange ResinL-shaped Cation-selective Membranes
check_url/55313?article_type=t

Play Video
PDF
DOI
DOWNLOAD MATERIALS LIST
Cite This Article
Kim, M., Rhee, H., Kang, J. Y., Kim, T. S., Kwak, R. Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone. J. Vis. Exp. (120), e55313, doi:10.3791/55313 (2017).
Download Citation
Reprints and Permissions

View Video

✖

To prove you're not a robot, please enter the text in the image below

CAPTCHA Image
Play CAPTCHA Audio
Refresh Image