Modeling and Simulation of Translocation Phenomenon in a Solid State Nanopore for Nanoparticle Separation

Solid state nanopore is a potential candidate for separation of nanoparticles or biomolecules such as proteins, DNA, and RNA. However, efficient separation of particles through nanopores is a challenging task as a number of factors such as externally applied voltage, size and charge density of particle, size and charge density of membrane pore, and the concentration of bulk electrolyte influence the translocation behavior of nanoparticles through pores. This paper uses a mathematical model based on Poisson–Nernst–Plank equations along with Navier-Stokes equations to systematically study these factors. Membrane pore surface charge is found to be a vital parameter in this seperation process. Numerical results reveal that efficient separation of high density lipoprotein (HDL) from low density lipoprotein (LDL) in a 0.2 M KCL solution (resembling blood buffer) through a 150 nm pore is possible if the pore surface charge density is around −4.0 mC/m².