title: Enhancement of dielectrophoresis using fractal gold nanostructured electrodes.
abstract: Dielectrophoretic motions of Saccharomyces cerevisiae (yeast) cells and colloidal gold are investigated using electrochemically modified electrodes exhibiting fractal topology. Electrodeposition of gold on electrodes generated repeated patterns with a fern-leaf type self-similarity. A particle tracking algorithm is used to extract dielectrophoretic particle velocities using fractal and planar electrodes in two different medium conductivities. The results show increased dielectrophoretic force when using fractal electrodes. Strong negative dielectrophoresis of yeast cells in high-conductivity media (1.5 S/m) is observed using fractal electrodes, while no significant motion is present using planar electrodes. Electrical impedance at the electrode/electrolyte interface is measured using impedance spectroscopy technique. Stronger electrode polarization (EP) effects are reported for planar electrodes. Decreased EP in fractal electrodes is considered as a reason for enhanced dielectrophoretic response.
authors.affiliation: Department of Mechanical Engineering, Southern Methodist University, Dallas, TX, USA.
authors.forename: Anil
authors.initials: A
authors.lastname: Koklu
authors.affiliation: Department of Mechanical Engineering, Southern Methodist University, Dallas, TX, USA.
authors.forename: Ahmet C
authors.initials: AC
authors.lastname: Sabuncu
authors.affiliation: Department of Mechanical Engineering, Southern Methodist University, Dallas, TX, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Beskok
mesh_terms: D000465:Algorithms; D017097:Electric Impedance; D004560:Electricity; D004586:Electrophoresis / Q000295:instrumentation / Q000379:methods; D017709:Fractals; D017979:Gold Colloid; D053768:Metal Nanoparticles; D008839:Microelectrodes; D009038:Motion; D049329:Nanostructures / Q000737:chemistry; D010316:Particle Size; D012441:Saccharomyces cerevisiae; D013499:Surface Properties
chemical_list: D017979:Gold Colloid
keywords: Dielectric spectroscopy; Dielectrophoresis; Fractal gold nanostructures