Alternating current dielectrophoresis of biomacromolecules: The interplay of electrokinetic effects

Dielectrophoresis is a powerful technique for the handling of bioparticles ranging in size and structure from cells to proteins. The surge in experimental research on dielectrophoretic manipulation of biomacromolecules in recent years demands a renewed consideration of tools leveraging micro- and nanofabrication for dielectrophoresis. One aspect of such platforms that is less explored in literature is the volumetric electrokinetic flows generated in response to an alternating current (AC) potential at the electrode-electrolyte interface such as AC electroosmosis and AC electrothermal flows. Those electrokinetic flows may interact with the dielectrophoretic force in certain experimental conditions. Hence, we provide a concise overview of the theory behind those phenomena and point out the key parameters for consideration and optimization. We further summarize experimental techniques for dielectrophoresis of the two most extensively studied biomacromolecules, DNA and protein molecules, and elaborate on their potential applications in separation, and mass transport for biosensing devices.