Pore length- and ion concentration-dependent ionic current in cylindricalnanopores: an atomistic molecular dynamics study

Abstract

The sensing of individual molecules as they pass through nanopores under an external field is a popular research field. The approach is simply based on the detectable temporary blockades in the ionic current as the molecules pass through the nanopores. These signatures of the current have been shown to be a function of nanoparticle and nanopore size and geometry as well as the external electric field. However, models developed in this context fail to predict the experimentally observed behavior in technologically important shorter nanopores. Here we present atomistic molecular dynamics simulation results from colloidal nanoparticle translocation through mid-to-low aspect ratio charged nanopores under an external field. We show that not only the pore length but also the ion concentration of the media and the nanoparticle charge have important effects on the ionic current.