Dielectrophoretic Trapping of Single Bacteria at Carbon Nanofiber Nanoelectrode Arrays^†

We present an ac dielectrophoretic (DEP) technique for single-cell trapping using embedded carbon nanofiber (CNF) nanoelectrode arrays (NEAs). NEAs fabricated by inlaying vertically aligned carbon nanofibers in SiO₂ matrix are applied as “points-and-lid” DEP devices in aqueous solution. The miniaturization of the electrode size provides a highly focused electrical field with the gradient enhanced by orders of magnitude. This generates extremely large positive DEP forces near the electrode surface and traps small bioparticles against strong hydrodynamic forces. This technology promises new capabilities to perform novel cell biology experiments at the nanoscale. We anticipate that the bottom-up approach of such nano-DEP devices allows the integration of millions of nanolectrodes deterministically in lab-on-a-chip devices and will be generally useful for manipulating submicron particles.