Optimizing particle collection for enhanced surface-based biosensors

In this article, electrode structures that combine dielectrophoretic effects with electrohydrodynamic fluid flow to concentrate particles on active sensor surfaces were presented. To optimize the collection effect on a surface, a novel electrode configuration called zipper electrodes has been developed. The local enrichment effect of these electrodes is such that particles at local concentration of 5/spl times/10/sup 3/ spores/mL can be collected using a single electrode pad. The fluid flow induced in the bulk flow is an efficient mechanism especially for very small particles, since the dielectrophoretic forces working on these particles are normally very small and do not penetrate the liquid as far as the vortex induced by combined dielectrophoresis/fluid flow does. The bulk flow makes it also a very versatile method that can extract a wide range of particles out of the liquid.