de.mpg.escidoc.pubman.appbase.FacesBean
English
 
Help Guide Disclaimer Contact us Login
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

The drift approximation solves the Poisson, Nernst-Planck, and continuum equations in the limit of large external voltages

MPS-Authors
http://pubman.mpdl.mpg.de/cone/persons/resource/persons95816

Von Kitzing,  Eberhard
Department of Cell Physiology, Max Planck Institute for Medical Research, Max Planck Society;

Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Syganov, A., & Von Kitzing, E. (1999). The drift approximation solves the Poisson, Nernst-Planck, and continuum equations in the limit of large external voltages. European Biophysics Journal, 28(5), 393-414. doi:10.1007/s002490050223.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0024-A287-D
Abstract
Nearly linear current-voltage curves are frequently found in biological ion channels. Using the drift limit of the substantially non-linear Poisson-Nernst-Planck equations, we explain such behavior of diffusion-controlled charge transport systems. Starting from Gauss' law, drift, and continuity equations we derive a simple analytical current-voltage relation, which accounts for this deviation from linearity. As shown previously, the drift limit of the Nernst-Planck equation applies if the total electric current is dominated by the electric field, and integral contributions from concentration gradients are small. The simple analytical form of the drift current-voltage relations makes it an ideal tool to analyze experiment current-voltage curves. We also solved the complete Poisson-Nernst-Planck equations numerically, and determined current-voltage curves over a wide range of voltages, concentrations, and Debye lengths. The simulation fully supports the analytical estimate that the current-voltage curves of simple charge transport systems are dominated by the drift mechanism. Even those relations containing the most extensive approximations remained qualitatively within the correct order of magnitude