Fabrication and integration of planar electrodes for contactless conductivity detection on polyester‐toner electrophoresis microchips
- 11 June 2008
- journal article
- microfluidics and-miniaturization
- Published by Wiley in Electrophoresis
- Vol. 29 (11), 2260-2265
- https://doi.org/10.1002/elps.200700761
Abstract
In this report, we describe the microfabrication and integration of planar electrodes for contactless conductivity detection on polyester‐toner (PT) electrophoresis microchips using toner masks. Planar electrodes were fabricated by three simple steps: (i) drawing and laser‐printing the electrode geometry on polyester films, (ii) sputtering deposition onto substrates, and (iii) removal of toner layer by a lift‐off process. The polyester film with anchored electrodes was integrated to PT electrophoresis microchannels by lamination at 120°C in less than 1 min. The electrodes were designed in an antiparallel configuration with 750 μm width and 750 μm gap between them. The best results were recorded with a frequency of 400 kHz and 10 Vpp using a sinusoidal wave. The analytical performance of the proposed microchip was evaluated by electrophoretic separation of potassium, sodium and lithium in 150 µm wide×6 µm deep microchannels. Under an electric field of 250 V/cm the analytes were successfully separated in less than 90 s with efficiencies ranging from 7000 to 13 000 plates. The detection limits (S/N = 3) found for K+, Na+, and Li+ were 3.1, 4.3, and 7.2 μmol/L, respectively. Besides the low‐cost and instrumental simplicity, the integrated PT chip eliminates the problem of manual alignment and gluing of the electrodes, permitting more robustness and better reproducibility, therefore, more suitable for mass production of electrophoresis microchips.Keywords
This publication has 45 references indexed in Scilit:
- Micro Total Analysis Systems. Latest Advancements and TrendsAnalytical Chemistry, 2006
- Electrokinetic control of fluid in plastified laser-printed poly(ethylene terephthalate)-toner microchipsAnalytical and Bioanalytical Chemistry, 2005
- Electrophoresis microchip fabricated by a direct‐printing process with end‐channel amperometric detectionElectrophoresis, 2004
- Micro Total Analysis Systems. Recent DevelopmentsAnalytical Chemistry, 2004
- Nanofabrication: Conventional and nonconventional methodsElectrophoresis, 2001
- Capillary electrophoresis on microchipElectrophoresis, 2000
- Polymer microfabrication methods for microfluidic analytical applicationsElectrophoresis, 1999
- Micro Total Analysis Systems: Microfluidic Aspects, Integration Concept and ApplicationsTopics in Current Chemistry, 1998
- Micromachining a Miniaturized Capillary Electrophoresis-Based Chemical Analysis System on a ChipScience, 1993
- Miniaturized total chemical analysis systems: A novel concept for chemical sensingSensors and Actuators B: Chemical, 1990