title: Asymmetric ion track nanopores for sensor technology. Reconstruction of pore profile from conductometric measurements.
abstract: We reconstruct the profile of asymmetric ion track nanopores from an algorithm developed for conductometric measurements of symmetric nanopores. The validity of the reconstruction is supported by FESEM observations. Our analysis reveals that asymmetric pores fabricated by one-sided etching are funnel-like and not conical. The analysis provides the constriction diameter and the pore profile as a function of etching time. The reconstruction of the pore profile defines the starting conditions of asymmetric nanopores at breakthrough. The deviation from the conical shape is most pronounced at the pore tip. This critical zone dominates transport properties relevant to ion conductance, selectivity, current rectification, resistive pulse sensing and biosensors. The classical cone approximation used until now underestimates the tip diameter by a factor of two. As transport processes in nanopores depend in a highly nonlinear way on the constriction diameter the presented reconstruction must be taken into account when studying ionic and molecular transport processes in asymmetric pores.
authors.affiliation: Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Joliot-Curie street 6, 141980 Dubna, Russia. The International University 'Dubna', Faculty of Natural and Engineering Sciences, Universitetskaya street 19, 141980 Dubna, Russia.
authors.forename: Pavel Yu
authors.initials: PY
authors.lastname: Apel
authors.forename: Irina V
authors.initials: IV
authors.lastname: Blonskaya
authors.forename: Oleg L
authors.initials: OL
authors.lastname: Orelovitch
authors.forename: Bozena A
authors.initials: BA
authors.lastname: Sartowska
authors.forename: Reimar
authors.initials: R
authors.lastname: Spohr