The Influence of Electric Field Intensity and Particle Length on the Electrokinetic Transport of Cylindrical Particles Passing through Nanopore

Abstract

The electric transport of nanoparticles passing through nanopores leads to a change in the ion current, which is essential for the detection technology of DNA sequencing and protein determination. In order to further illustrate the electrokinetic transport mechanism of particles passing through nanopores, a fully coupled continuum model is constructed by using the arbitrary Lagrangian–Eulerian (ALE) method. The model consists of the electric field described by the Poisson equation, the concentration field described by Nernst–Planck equation, and the flow field described by the Navier–Stokes equation. Based on this model, the influence of imposed electric field and particle length on the electrokinetic transport of cylindrical particles is investigated. It is found firstly the translation velocities for the longer particles remain constant when they locate inside the nanopore. Both the ion current blockade effect and the ion current enhancement effect occur when cylindrical particles enter and exit the nanopore, respectively, for the experimental parameters employed in this research. Moreover, the particle translation velocity and current fluctuation amplitude are dominated by the electric field intensity, which can be used to adjust the particle transmission efficiency and the ion current detectability. In addition, the increase in particle length changes the particle position corresponding to the peak value of the ion current, which contributes to distinguishing particles with different lengths as well.

Electrokinetic translocation of a deformable nanoparticle controlled by field effect in nanopores

“…It can be seen from previous studies [47,51] that the particles distribute below the nanopore randomly will move to the middle of the nanopore gradually, that is, they will move upward along the central axis of the nanopore. Therefore, the initial position of the particle is placed below the nanopore to simplify the process of simulation and analysis.…”

Large-scale production of polyimide micropore-based flow cells for detecting nano-sized particles in fluids

“…Injecting polystyrene (PS) nanoparticles into the Cis chamber and applying a negative voltage force them to translocate through the chamber since they are negatively charged at pH 7.5. 13,14 Furthermore, it is possible to determine the electro-kinetic acceleration of nanoparticles by their translocation times based on their stimulus voltage and nanopore length. As faster translocations imply greater surface charges of the nanoparticle, the zeta potential of the particle is measured as the slope of translocation time with voltage.…”

“…Injecting polystyrene (PS) nanoparticles into the Cis chamber and applying a negative voltage force them to translocate through the chamber since they are negatively charged at pH 7.5. 13,14…”