Dresden 2009 – scientific programme
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BP: Fachverband Biologische Physik
BP 11: Novel Methods
BP 11.5: Talk
Tuesday, March 24, 2009, 15:30–15:45, ZEU 260
Spatial chemical gradient measurements in microfluidic channels by arrays of nano-gap electrodes — •Enno Kätelhön1,2, Marcel A. G. Zevenbergen3, Edgar D. Goluch3, Serge G. Lemay3, Andreas Offenhäusser1,2, and Bernhard Wolfrum1,2 — 1IBN-2, Forschungszentrum Jülich GmbH, Germany — 2JARA- Fundamentals of Future Information Technology — 3Kavli Institute of Nanoscience, Delft University of Technology, the Netherlands
In recent years, microfluidic devices have received growing attention along with the proceeding miniaturization of electrochemical sensors. In particular regarding biophysical applications, there is an increasing interest due to the potential to establish specific chemical environments inside of microfluidic systems. Since these systems feature a laminar flow trait, they allow setting up highly defined chemical gradient fields that are exclusively based on diffusive mixing. Thus, cell growth characteristics can be investigated concurrently within one experimental setup in different chemical environments.
We present a new method to evaluate the mixing gradient of redox- and non redox-active substances inside of a micro scaled flow. Our system features a set of interdigitated nano-electrode arrays that is incorporated into a PDMS microchannel. By this means, we can record cyclic voltammograms simultaneously at different locations inside of the channel as well as determine the concentration of the redox-active substance at specific spots. Owing to the nano scaled redox cycling approach, our method exhibits a high special resolution and a large current amplification.