Modeling and simulation of nanoparticle separation through a solid-state nanopore.

Recent experimental studies show that electrokinetic phenomena such as electroosmosis and electrophoresis can be used to separate nanoparticles on the basis of their size and charge using nanopore-based devices. However, the efficient separation through a nanopore depends on 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. To design an efficient nanopore-based separation platform, a continuum-based mathematical model is used for fluid.

SEM-induced shrinking of solid-state nanopores for single molecule detection.

We have investigated the mechanism by which the diameter of solid-state nanopores is reduced by a scanning electron microscope. The process depends on beam parameters such as the accelerating voltage and electron flux and does not involve simple electron-beam-induced deposition of hydrocarbon contaminants. Instead, it is an energy-dependent process that involves material flow along the surface of the nanopore membrane.

Chemically modified solid state nanopores for high throughput nanoparticle separation.

The separation of biomolecules and other nanoparticles is a vital step in several analytical and diagnostic techniques. Towards this end we present a solid state nanopore-based set-up as an efficient separation platform. The translocation of charged particles through a nanopore was first modeled mathematically using the multi-ion model and the surface charge density of the nanopore membrane was identified as a critical parameter that determines the selectivity of the membrane and the throughput of the separation process.