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Lattice-Boltzmann Simulations of Ionic Current Modulation by DNA Translocation
Sylvain Reboux1, Fabrizio Capuani1, Daan Frenkel1
1FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
Journal of Chemical Theory and Computation
|December 3, 2015
Summary
DNA translocation through nanopores typically reduces ionic current, but can enhance it at low salt concentrations. Localized charge probes on pore walls reveal weak, observable ionic current modulations during DNA transport.
Area of Science:
- Biophysics
- Nanotechnology
- Computational Science
Background:
- Nanopore technology offers a platform for DNA analysis.
- Understanding ion transport during DNA translocation is crucial for sensing applications.
- Electrokinetic effects govern ion and fluid behavior in nanopores.
Purpose of the Study:
- To numerically investigate the impact of DNA translocation on nanopore ionic current.
- To explore the influence of salt concentration and pore geometry on this effect.
- To assess the potential for detecting DNA translocation via ionic current measurements.
Main Methods:
- Coarse-grained modeling of DNA translocation.
- Solving electrokinetic equations at the Poisson-Boltzmann level for microions.
- Coupling with lattice-Boltzmann equation for solvent hydrodynamics.
Main Results:
- DNA translocation generally reduces ionic current, except at low salt concentrations where enhancement is observed.
- In unstructured pores, DNA's helical charge distribution has no significant effect on current.
- Localized charge probes on pore walls induce weak, but potentially observable, ionic current modulations.
Conclusions:
- Ionic current modulation during DNA translocation is dependent on salt concentration and pore characteristics.
- The findings suggest possibilities for label-free DNA detection using nanopore sensors.
- Further experimental validation is warranted for the observed charge probe effects.
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