Electrostatics of polymer translocation events in electrolyte solutions

Sahin Buyukdagli, Tapio Ala-Nissilä

Research output: Contribution to journalArticleScientificpeer-review

2 Citations (Scopus)
291 Downloads (Pure)

Abstract

We develop an analytical theory that accounts for the image and surface charge interactions between a charged dielectric membrane and a DNA molecule translocating through the membrane. Translocation events through neutral carbon-based membranes are driven by a competition between the repulsive DNA-image-charge interactions and the attractive coupling between the DNA segments on the trans and the cis sides of the membrane. The latter effect is induced by the reduction of the coupling by the dielectric membrane. In strong salt solutions where the repulsive image-charge effects dominate the attractive trans-cis coupling, the DNA molecule encounters a translocation barrier of ∼10 kBT. In dilute electrolytes, the trans-cis coupling takes over image-charge forces and the membrane becomes a metastable attraction point that can trap translocating polymers over long time intervals. This mechanism can be used in translocation experiments in order to control DNA motion by tuning the salt concentration of the solution.

Original languageEnglish
Article number014902
Pages (from-to)1-11
JournalJournal of Chemical Physics
Volume145
Issue number1
DOIs
Publication statusPublished - 7 Jul 2016
MoE publication typeA1 Journal article-refereed

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