Electrohydrodynamic removal of non-specific colloidal adsorption at electrode interfaces.

This communication reports the use of an electrohydrodynamic surface shear force to selectively manipulate colloid-surface interactions. We demonstrate the selection of strongly (specifically) bound biomolecule-functionalized colloidal beads over more weakly (non-specifically) bound beads using a tuneable alternating current electrohydrodynamic (ac-EHD) force, which drives lateral fluid motion within a few nanometers of an electrode surface. By externally "tuning" the strength of the ac-EHD force, we demonstrate a significant enhancement of capture efficiency for specifically bound colloids, along with a removal of the adsorption of non-specific colloidal beads - a process which may be observed in real-time.