Ion Current Rectification Behavior of Conical Nanopore Filled with Spatially Distributed Fixed Charges

Ion current rectification (ICR) phenomena in conical nanopore have been extensively investigated since its early discovery. Several theoretical explanations were proposed to quantitatively describe ICR behavior and to interpret the influences of various configurations. However, if the inner surface of nanopore is modified with charged molecules or even polymers, the charge species should not be considered simply as mass points. Consequently, the spatial charge distribution in the confined nanopore domains have no reason to be neglected. Here we proposed a theoretical model to interrogate this kind of ICR behavior by using Poisson, Nernst-Planck (PNP) equation. The influence of a series of parameters including ion concentration, bias potential, nanopore dimension and charge density and its spatial distribution on the mass transfer properties of various nanopores, especially the ICR behaviors, are investigated. This study is expected to extend the understanding of nanopore ICR characteristics and open up ne...