Electrohydrodynamic removal of non-specific colloidal adsorption at electrode interfaces

Abstract

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.