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DNA Strands Attached Inside Single Conical Nanopores: Ionic Pore Characteristics and Insight into DNA Biophysics

Single nanopores attract a great deal of scientific interest as a basis for biosensors and as a system to study the interactions and behavior of molecules in a confined volume. Tuning the geometry and surface chemistry of nanopores helps create devices that control transport of ions and molecules in...

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Detalles Bibliográficos
Autores principales: Nguyen, Gael, Howorka, Stefan, Siwy, Zuzanna S.
Formato: Texto
Lenguaje:English
Publicado: Springer-Verlag 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3030949/
https://www.ncbi.nlm.nih.gov/pubmed/21120653
http://dx.doi.org/10.1007/s00232-010-9328-4
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author Nguyen, Gael
Howorka, Stefan
Siwy, Zuzanna S.
author_facet Nguyen, Gael
Howorka, Stefan
Siwy, Zuzanna S.
author_sort Nguyen, Gael
collection PubMed
description Single nanopores attract a great deal of scientific interest as a basis for biosensors and as a system to study the interactions and behavior of molecules in a confined volume. Tuning the geometry and surface chemistry of nanopores helps create devices that control transport of ions and molecules in solution. Here, we present single conically shaped nanopores whose narrow opening of 8 or 12 nm is modified with single-stranded DNA molecules. We find that the DNA occludes the narrow opening of nanopores and that the blockade extent decreases with the ionic strength of the background electrolyte. The results are explained by the ionic strength dependence of the persistence length of DNA. At low KCl concentrations (10 mM) the molecules assume an extended and rigid conformation, thereby blocking the pore lumen and reducing the flow of ionic current to a greater extent than compacted DNA at high salt concentrations. Attaching flexible polymers to the pore walls hence creates a system with tunable opening diameters in order to regulate transport of both neutral and charged species.
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spelling pubmed-30309492011-03-16 DNA Strands Attached Inside Single Conical Nanopores: Ionic Pore Characteristics and Insight into DNA Biophysics Nguyen, Gael Howorka, Stefan Siwy, Zuzanna S. J Membr Biol Article Single nanopores attract a great deal of scientific interest as a basis for biosensors and as a system to study the interactions and behavior of molecules in a confined volume. Tuning the geometry and surface chemistry of nanopores helps create devices that control transport of ions and molecules in solution. Here, we present single conically shaped nanopores whose narrow opening of 8 or 12 nm is modified with single-stranded DNA molecules. We find that the DNA occludes the narrow opening of nanopores and that the blockade extent decreases with the ionic strength of the background electrolyte. The results are explained by the ionic strength dependence of the persistence length of DNA. At low KCl concentrations (10 mM) the molecules assume an extended and rigid conformation, thereby blocking the pore lumen and reducing the flow of ionic current to a greater extent than compacted DNA at high salt concentrations. Attaching flexible polymers to the pore walls hence creates a system with tunable opening diameters in order to regulate transport of both neutral and charged species. Springer-Verlag 2010-12-01 2011 /pmc/articles/PMC3030949/ /pubmed/21120653 http://dx.doi.org/10.1007/s00232-010-9328-4 Text en © The Author(s) 2010 https://creativecommons.org/licenses/by-nc/4.0/ This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
spellingShingle Article
Nguyen, Gael
Howorka, Stefan
Siwy, Zuzanna S.
DNA Strands Attached Inside Single Conical Nanopores: Ionic Pore Characteristics and Insight into DNA Biophysics
title DNA Strands Attached Inside Single Conical Nanopores: Ionic Pore Characteristics and Insight into DNA Biophysics
title_full DNA Strands Attached Inside Single Conical Nanopores: Ionic Pore Characteristics and Insight into DNA Biophysics
title_fullStr DNA Strands Attached Inside Single Conical Nanopores: Ionic Pore Characteristics and Insight into DNA Biophysics
title_full_unstemmed DNA Strands Attached Inside Single Conical Nanopores: Ionic Pore Characteristics and Insight into DNA Biophysics
title_short DNA Strands Attached Inside Single Conical Nanopores: Ionic Pore Characteristics and Insight into DNA Biophysics
title_sort dna strands attached inside single conical nanopores: ionic pore characteristics and insight into dna biophysics
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3030949/
https://www.ncbi.nlm.nih.gov/pubmed/21120653
http://dx.doi.org/10.1007/s00232-010-9328-4
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