Spatial profiles of electrical conductivity, fluid admittance and water flow in a charged nanopore


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The transport of charged particles and water through nanofluidic pores is governed by the concentration, potential and pressure gradients. Better understanding of the interplay of these forces, of the resulting fluxes of charged particles and of the fluid (water) flow is critical for faster and more reliable delivery of drugs through nanopores. It is also important for better understanding of the mechanism of exocytosis of hormones, transmitters or peptides through fusion pores. Finally, the characterization of the transport of charged particles and water through such nanopores in terms of experimentally measurable variables (nanopore conductance and fluidic admittance and flow) is needed including the evaluation of their spatial distributions. We simulated the transport of charged particles (K+, glutamate-, Na+ and Cl-) and water using a coupled set of Poisson–Nernst–Planck and Navier–Stokes equations. The electrical conductivity is the highest near the wall of the nanopore owing to the presence of fixed charges. The fluid specific admittance is fairly uniform, but diminishes near the wall becoming zero at the wall (no-slip). Approximately in the middle between the pore center and the pore wall the fluid admittance and the water flow peak. The pressure perturbations may produce the current reversal.

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Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2012: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational (Volume 2)
Published: June 18, 2012
Pages: 329 - 332
Industry sectors: Advanced Materials & Manufacturing | Sensors, MEMS, Electronics
Topic: Micro & Bio Fluidics, Lab-on-Chip
ISBN: 978-1-4665-6275-2