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Determination of Zeta Potential via Nanoparticle Translocation Velocities through a Tunable Nanopore: Using DNA-modified Particles as an Example
Published on: October 26, 2016
Electrokinetic particle translocation through a nanopore containing a floating electrode
Mingkan Zhang1, Ye Ai, Ashutosh Sharma
1Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, VA 23529-0247, USA.
Electrophoresis
|June 29, 2011
Summary
A floating electrode in a nanopore can trap DNA nanoparticles via induced-charge electroosmosis (ICEO) at high electric fields. This setup also increases ionic current but has minimal impact on current deviation when the particle is distant.
Area of Science:
- Nanotechnology
- Physical Chemistry
- Biophysics
Background:
- Electrokinetic phenomena govern particle and fluid motion in micro/nanoscale devices.
- Floating electrodes introduce unique electrical and hydrodynamic interactions within confined geometries.
- Understanding nanoparticle translocation is crucial for nanopore sensing and drug delivery.
Purpose of the Study:
- To investigate the electrokinetic translocation of DNA nanoparticles through a nanopore with a floating electrode.
- To analyze the influence of induced-charge electroosmosis (ICEO) and electrostatic interactions on nanoparticle mobility.
- To determine the effect of the floating electrode on ionic current.
Main Methods:
- Solving coupled Poisson-Nernst-Planck (PNP) equations for ion transport.
- Utilizing modified Stokes equations to model fluid flow.
- Developing a continuum model to simulate particle-nanopore-electrode interactions.
Main Results:
- The floating electrode can induce ICEO, leading to nanoparticle trapping near the electrode at high electric fields.
- Electrostatic interactions between the particle and electrode are negligible when their electrical double layers (EDLs) do not overlap.
- The floating electrode increases ionic current within the nanopore.
- The effect of the floating electrode on current deviation is limited when the particle is far from the pore.
Conclusions:
- Floating electrodes significantly alter nanoparticle electrokinetics in nanopores, enabling potential trapping mechanisms.
- ICEO is a dominant factor in nanoparticle behavior near the floating electrode.
- The floating electrode enhances ionic current, offering possibilities for signal amplification in nanopore devices.
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