Field effect regulation of DNA translocation through a nanopore.

Field effect regulation of DNA nanoparticle translocation through a nanopore using a gate electrode is investigated using a continuum model, composed of the coupled Poisson-Nernst-Planck equations for the ionic mass transport and the Navier-Stokes equations for the hydrodynamic field. The field effect regulation of the DNA translocation relies on the induced electroosmotic flow (EOF) and the particle-nanopore electrostatic interaction. When the electrical double layers (EDLs) formed adjacent to the DNA nanoparticle and the nanopore wall are overlapped, the particle-nanopore electrostatic interaction could dominate over the EOF effect, which enables the DNA trapping inside the nanopore when the applied electric field is relatively low. However, the particle-nanopore electrostatic interaction becomes negligible if the EDLs are not overlapped. When the applied electric field is relatively high, a negative gate potential can slow down the DNA translocation by an order of magnitude, compared to a floating gate electrode. The field effect control offers a more flexible and electrically compatible approach to regulate the DNA translocation through a nanopore for DNA sequencing.