title: Characterization and application of ion track-etched nanopores
creator: Schiedt, Birgitta
subject: ddc-530
subject: 530 Physics
description: This thesis investigates the ionic transport properties of single, conical nanopores in polymers, as well as their applicability as single-molecule sensors. The pores were produced by selective etching of the damaged zones of energetic heavy ions (track-etching technique). More basic investigations of the shape of track-etched pores (by small-angle X-ray scattering, electron microscopy and conductometry) are also included, revealing smaller pore sizes on top of a membrane than inside the pore. Conical track-etched nanopores are cation selective and show asymmetric I-V characteristics, depending on pH value and concentration of the electrolyte. These properties result from their negative surface charges created during the etching process, which lead to an intrinsic asymmetric electric potential long the pore axis. Experiments show a maximum for the rectification at about 0.1 M KCl, in accordance with theoretical calculations. The selectivity of the pores depends on the direction of an applied concentration gradient, being higher for the lower concentration facing the small opening of the pore, again in agreement with calculations. The pores transport properties are strongly influenced by small concentrations of divalent cations. Conical polyimide pores have been found suitable to detect single DNA molecules passing through them via changes in the ionic current.
date: 2007
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/7426/1/Diss_BSchiedt.pdf
identifier: DOI:10.11588/heidok.00007426
identifier: urn:nbn:de:bsz:16-opus-74264
identifier:   Schiedt, Birgitta  (2007) Characterization and application of ion track-etched nanopores.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/7426/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng