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In-plane alloy electrodes for capacitively coupled contactless conductivity detection in poly(methylmethacrylate) electrophoretic chips
journal contribution
posted on 2023-05-17, 21:37 authored by Adam GaudryAdam Gaudry, Michael BreadmoreMichael Breadmore, Rosanne GuijtA simple method for producing PMMA electrophoresis microchips with in-plane electrodes for capacitively coupled contactless conductivity detection is presented. One PMMA plate (channel plate) is embossed with the microfluidic and electrode channels and lamination bonded to a blank PMMA cover plate of equal dimensions. To incorporate the electrodes, the bonded chip is heated to 80 Celsius degree, above the melting point of the alloy (~70 Celsius degree) and below the glass transition temperature of the PMMA (~105 Celsius degree), and the molten alloy drawn into the electrode channels with a syringe before being allowed to cool and harden. A 0.5 mm diameter stainless steel pin is then inserted into the alloy filled reservoirs of the electrode channels to provide external connection to the capacitively coupled contactless conductivity detection detector electronics. This advance provides for a quick and simple manufacturing process and negates the need for integrating electrodes using costly and time-consuming thin film deposition methods. No additional detector cell mounting structures were required and connection to the external signal processing electronics was achieved by simply slipping commercially available shielded adaptors over the pins. With a non-optimised electrode arrangement consisting of a 1 mm detector gap and 100 um insulating distance, rapid separations of ammonium, sodium and lithium (<22 s) yielded LODs of approximately 1.5-3.5 ppm.
Funding
Dept of Prime Minister & Cabinet
Australian Federal Police
History
Publication title
ElectrophoresisVolume
34Issue
20-21Pagination
2980-2987ISSN
0173-0835Department/School
School of Natural SciencesPublisher
Wiley - V C H Verlag GmbH & Co. KGaAPlace of publication
GermanyRights statement
Copyright 2013 2013 WILEY-VCH Verlag GmbH & Co.Repository Status
- Restricted