Advanced

On-chip label-free protein analysis with downstream electrodes for direct removal of electrolysis products

Saar, Kadi L.; Zhang, Yingbo; Müller, Thomas; Kumar, Challa P.; Devenish, Sean; Lynn, Andrew; Łapińska, Urszula; Yang, Xiaoting LU ; Linse, Sara LU and Knowles, Tuomas P.J. (2017) In Lab on a Chip 18(1). p.162-170
Abstract

The ability to apply highly controlled electric fields within microfluidic devices is valuable as a basis for preparative and analytical processes. A challenge encountered in the context of such approaches in conductive media, including aqueous buffers, is the generation of electrolysis products at the electrode/liquid interface which can lead to contamination, perturb fluid flows and generally interfere with the measurement process. Here, we address this challenge by designing a single layer microfluidic device architecture where the electric potential is applied outside and downstream of the microfluidic device while the field is propagated back to the chip via the use of a co-flowing highly conductive electrolyte solution that forms... (More)

The ability to apply highly controlled electric fields within microfluidic devices is valuable as a basis for preparative and analytical processes. A challenge encountered in the context of such approaches in conductive media, including aqueous buffers, is the generation of electrolysis products at the electrode/liquid interface which can lead to contamination, perturb fluid flows and generally interfere with the measurement process. Here, we address this challenge by designing a single layer microfluidic device architecture where the electric potential is applied outside and downstream of the microfluidic device while the field is propagated back to the chip via the use of a co-flowing highly conductive electrolyte solution that forms a stable interface at the separation region of the device. The co-flowing electrolyte ensures that all the generated electrolysis products, including Joule heat and gaseous products, are flowed away from the chip without coming into contact with the analytes while the single layer fabrication process where all the structures are defined lithographically allows producing the devices in a simple yet highly reproducible manner. We demonstrate that by allowing stable and effective application of electric fields in excess of 100 V cm-1, the described platform provides the basis for rapid separation of heterogeneous mixtures of proteins and protein complexes directly in their native buffers as well as for the simultaneous quantification of their charge states. We illustrate this by probing the interactions in a mixture of an amyloid forming protein, amyloid-β, and a molecular chaperone, Brichos, known to inhibit the process of amyloid formation. The availability of a platform for applying stable electric fields and its compatibility with single-layer soft-lithography processes opens up the possibility of separating and analysing a wide range of molecules on chip, including those with similar electrophoretic mobilities.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Lab on a Chip
volume
18
issue
1
pages
9 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:85038617396
  • wos:000418367800014
ISSN
1473-0197
DOI
10.1039/c7lc00797c
language
English
LU publication?
yes
id
8261b060-0484-46cb-83ea-ddbfad466f03
date added to LUP
2018-01-04 14:34:29
date last changed
2018-04-08 05:03:23
@article{8261b060-0484-46cb-83ea-ddbfad466f03,
  abstract     = {<p>The ability to apply highly controlled electric fields within microfluidic devices is valuable as a basis for preparative and analytical processes. A challenge encountered in the context of such approaches in conductive media, including aqueous buffers, is the generation of electrolysis products at the electrode/liquid interface which can lead to contamination, perturb fluid flows and generally interfere with the measurement process. Here, we address this challenge by designing a single layer microfluidic device architecture where the electric potential is applied outside and downstream of the microfluidic device while the field is propagated back to the chip via the use of a co-flowing highly conductive electrolyte solution that forms a stable interface at the separation region of the device. The co-flowing electrolyte ensures that all the generated electrolysis products, including Joule heat and gaseous products, are flowed away from the chip without coming into contact with the analytes while the single layer fabrication process where all the structures are defined lithographically allows producing the devices in a simple yet highly reproducible manner. We demonstrate that by allowing stable and effective application of electric fields in excess of 100 V cm<sup>-1</sup>, the described platform provides the basis for rapid separation of heterogeneous mixtures of proteins and protein complexes directly in their native buffers as well as for the simultaneous quantification of their charge states. We illustrate this by probing the interactions in a mixture of an amyloid forming protein, amyloid-β, and a molecular chaperone, Brichos, known to inhibit the process of amyloid formation. The availability of a platform for applying stable electric fields and its compatibility with single-layer soft-lithography processes opens up the possibility of separating and analysing a wide range of molecules on chip, including those with similar electrophoretic mobilities.</p>},
  author       = {Saar, Kadi L. and Zhang, Yingbo and Müller, Thomas and Kumar, Challa P. and Devenish, Sean and Lynn, Andrew and Łapińska, Urszula and Yang, Xiaoting and Linse, Sara and Knowles, Tuomas P.J.},
  issn         = {1473-0197},
  language     = {eng},
  number       = {1},
  pages        = {162--170},
  publisher    = {Royal Society of Chemistry},
  series       = {Lab on a Chip},
  title        = {On-chip label-free protein analysis with downstream electrodes for direct removal of electrolysis products},
  url          = {http://dx.doi.org/10.1039/c7lc00797c},
  volume       = {18},
  year         = {2017},
}