Bubble-Free Operation of a Microfluidic Free-Flow Electrophoresis Chip with Integrated Pt Electrodes

Research output: Contribution to journalArticleAcademicpeer-review

56 Citations (Scopus)

Abstract

In order to ensure a stable and efficient separation in microfluidic free-flow electrophoresis (FFE) devices, various methods and chips have been presented until now. A major concern hereby is the generation of gas bubbles caused by electrolysis and the resulting disturbances in the position of the separated analyte lanes. Instable lane positions would lead to a decreased resolution in sample collection over time which certainly would be problematic when incorporating a stationary detector system. In contrast to our previous publications, in which we implemented laborious semipermeable membranes to keep bubbles outside the separation region, here we describe an electrochemical approach to suppress the electrolysis of water molecules and therefore bubble formation. This approach allowed a simpler and additionally a closed chip device with integrated platinum electrodes. With the use of this chip, the successful separation of three fluorescent compounds was demonstrated. Quinhydrone, which is a complex of hydroquinone and p-benzoquinone, was added only to the local flow streams along the electrodes, preventing mixing with the separation media and sample. The electrical current was generated via the oxidization and reduction of hydroquinone and p-benzoquinone up to a certain limit of the electrical current without gas formation. The separation stability was investigated for the chip with and without quinhydrone, and the results clearly indicated the improvement. In contrast to the device operating without quinhydrone, a 2.5-fold increase in resolution was achieved. Furthermore, separation was demonstrated within tens of milliseconds. This chemical approach with its high miniaturization possibilities offers an interesting alternative, in particular for low-current miniaturized FFE systems, in which large and open electrode reservoirs are not tolerable.
Original languageUndefined
Pages (from-to)4111-4118
Number of pages8
JournalAnalytical chemistry
Volume80
Issue number11
DOIs
Publication statusPublished - 1 Jun 2008

Keywords

  • METIS-252035
  • EWI-13010
  • IR-60699

Cite this

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title = "Bubble-Free Operation of a Microfluidic Free-Flow Electrophoresis Chip with Integrated Pt Electrodes",
abstract = "In order to ensure a stable and efficient separation in microfluidic free-flow electrophoresis (FFE) devices, various methods and chips have been presented until now. A major concern hereby is the generation of gas bubbles caused by electrolysis and the resulting disturbances in the position of the separated analyte lanes. Instable lane positions would lead to a decreased resolution in sample collection over time which certainly would be problematic when incorporating a stationary detector system. In contrast to our previous publications, in which we implemented laborious semipermeable membranes to keep bubbles outside the separation region, here we describe an electrochemical approach to suppress the electrolysis of water molecules and therefore bubble formation. This approach allowed a simpler and additionally a closed chip device with integrated platinum electrodes. With the use of this chip, the successful separation of three fluorescent compounds was demonstrated. Quinhydrone, which is a complex of hydroquinone and p-benzoquinone, was added only to the local flow streams along the electrodes, preventing mixing with the separation media and sample. The electrical current was generated via the oxidization and reduction of hydroquinone and p-benzoquinone up to a certain limit of the electrical current without gas formation. The separation stability was investigated for the chip with and without quinhydrone, and the results clearly indicated the improvement. In contrast to the device operating without quinhydrone, a 2.5-fold increase in resolution was achieved. Furthermore, separation was demonstrated within tens of milliseconds. This chemical approach with its high miniaturization possibilities offers an interesting alternative, in particular for low-current miniaturized FFE systems, in which large and open electrode reservoirs are not tolerable.",
keywords = "METIS-252035, EWI-13010, IR-60699",
author = "D. Kohlheyer and Eijkel, {Jan C.T.} and Stefan Schlautmann and {van den Berg}, Albert and Schasfoort, {Richardus B.M.}",
note = "10.1021/ac800275c",
year = "2008",
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Bubble-Free Operation of a Microfluidic Free-Flow Electrophoresis Chip with Integrated Pt Electrodes. / Kohlheyer, D.; Eijkel, Jan C.T.; Schlautmann, Stefan; van den Berg, Albert; Schasfoort, Richardus B.M.

In: Analytical chemistry, Vol. 80, No. 11, 01.06.2008, p. 4111-4118.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Bubble-Free Operation of a Microfluidic Free-Flow Electrophoresis Chip with Integrated Pt Electrodes

AU - Kohlheyer, D.

AU - Eijkel, Jan C.T.

AU - Schlautmann, Stefan

AU - van den Berg, Albert

AU - Schasfoort, Richardus B.M.

N1 - 10.1021/ac800275c

PY - 2008/6/1

Y1 - 2008/6/1

N2 - In order to ensure a stable and efficient separation in microfluidic free-flow electrophoresis (FFE) devices, various methods and chips have been presented until now. A major concern hereby is the generation of gas bubbles caused by electrolysis and the resulting disturbances in the position of the separated analyte lanes. Instable lane positions would lead to a decreased resolution in sample collection over time which certainly would be problematic when incorporating a stationary detector system. In contrast to our previous publications, in which we implemented laborious semipermeable membranes to keep bubbles outside the separation region, here we describe an electrochemical approach to suppress the electrolysis of water molecules and therefore bubble formation. This approach allowed a simpler and additionally a closed chip device with integrated platinum electrodes. With the use of this chip, the successful separation of three fluorescent compounds was demonstrated. Quinhydrone, which is a complex of hydroquinone and p-benzoquinone, was added only to the local flow streams along the electrodes, preventing mixing with the separation media and sample. The electrical current was generated via the oxidization and reduction of hydroquinone and p-benzoquinone up to a certain limit of the electrical current without gas formation. The separation stability was investigated for the chip with and without quinhydrone, and the results clearly indicated the improvement. In contrast to the device operating without quinhydrone, a 2.5-fold increase in resolution was achieved. Furthermore, separation was demonstrated within tens of milliseconds. This chemical approach with its high miniaturization possibilities offers an interesting alternative, in particular for low-current miniaturized FFE systems, in which large and open electrode reservoirs are not tolerable.

AB - In order to ensure a stable and efficient separation in microfluidic free-flow electrophoresis (FFE) devices, various methods and chips have been presented until now. A major concern hereby is the generation of gas bubbles caused by electrolysis and the resulting disturbances in the position of the separated analyte lanes. Instable lane positions would lead to a decreased resolution in sample collection over time which certainly would be problematic when incorporating a stationary detector system. In contrast to our previous publications, in which we implemented laborious semipermeable membranes to keep bubbles outside the separation region, here we describe an electrochemical approach to suppress the electrolysis of water molecules and therefore bubble formation. This approach allowed a simpler and additionally a closed chip device with integrated platinum electrodes. With the use of this chip, the successful separation of three fluorescent compounds was demonstrated. Quinhydrone, which is a complex of hydroquinone and p-benzoquinone, was added only to the local flow streams along the electrodes, preventing mixing with the separation media and sample. The electrical current was generated via the oxidization and reduction of hydroquinone and p-benzoquinone up to a certain limit of the electrical current without gas formation. The separation stability was investigated for the chip with and without quinhydrone, and the results clearly indicated the improvement. In contrast to the device operating without quinhydrone, a 2.5-fold increase in resolution was achieved. Furthermore, separation was demonstrated within tens of milliseconds. This chemical approach with its high miniaturization possibilities offers an interesting alternative, in particular for low-current miniaturized FFE systems, in which large and open electrode reservoirs are not tolerable.

KW - METIS-252035

KW - EWI-13010

KW - IR-60699

U2 - 10.1021/ac800275c

DO - 10.1021/ac800275c

M3 - Article

VL - 80

SP - 4111

EP - 4118

JO - Analytical chemistry

JF - Analytical chemistry

SN - 0003-2700

IS - 11

ER -