2016/06/21 by Georg Rempfer, Sascha Ehrhardt, Rempfer, Georg +5
Engineering · Earth and Planetary Sciences · #Nanopore and Nanochannel Transport Studies #Geophysical and Geoelectrical Methods #Electrokinetic Soil Remediation Techniques
paper · pdf · doi:10.48550/arxiv.1606.06432
Recent years have seen a surge of interest in nanopores because such\nstructures show a strong potential for characterizing nanoparticles, proteins,\nDNA, and even single molecules. These systems have been extensively studied in\nexperiment as well as by all-atom and coarse-grained simulations, with a strong\nfocus on DNA translocation. However, the equally interesting problem of\nparticle characterization using nanopores has received far less attention.\nHere, we theoretically investigate the translocation of a nanoparticle through\na conical nanocapillary. We use a model based on numerically solving the\ncoupled system of electrokinetic continuum equations, which we introduce in\ndetail. Based on our findings, we formulate basic guidelines for obtaining the\nmaximum current signal during the translocation event, which should be\ntransferable to other nanopore geometries. In addition, the dependence of the\nsignal strength on particle properties, such as surface charge and size, is\nevaluated. Finally, we identify conditions under which the translocation is\nprevented by the formation of a strong electro-osmotic barrier and show that\nthe particle may even become trapped at the pore orifice, without imposing an\nexternal hydrostatic pressure difference.\n