title: A simple method to fabricate electrochemical sensor systems with predictable high-redox cycling amplification.
abstract: In this paper an easy to fabricate SU8/glass-based microfluidic sensor is described with two closely spaced parallel electrodes for highly selective measurements using the redox cycling effect. By varying the length of the microfluidic entrance channel, a diffusion barrier is created for non-cycling species effectively increasing selectivity for redox cycling species. Using this sensor, a redox cycling amplification of ∼6500× is measured using the ferrocyanide redox couple. Moreover, a simple, but accurate analytical expression is derived that predicts the amplification factor based on the sensor geometry.
authors.affiliation: BIOS/Lab-on-Chip Group, MESA+ Institute for Nanotechnology, University of Twente, P. O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: M G
authors.initials: MG
authors.lastname: Straver
authors.forename: M
authors.initials: M
authors.lastname: Odijk
authors.forename: W
authors.initials: W
authors.lastname: Olthuis
authors.forename: A
authors.initials: A
authors.lastname: van den Berg
mesh_terms: D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D055616:Microtechnology / Q000379:methods*; D010084:Oxidation-Reduction