Surface-charge effects on the movement of a polyelectrolyte through a solid-state nanopore

¹ College of Life sciences and Biotechnology, School of Science, Beijing Jiaotong University, Beijing 100044, P.R. China
² University of Science and Technology of China, Hefei 230026, P.R. China

^a e-mail: dkjian@bjtu.edu.cn

Received: 22 July 2011
Revised: 30 March 2012
Accepted: 21 May 2012
Published online: 5 July 2012

Abstract

This contribution presents an electro-hydrodynamic method for establishing the relationship between the motion of a polyelectrolyte through a solid-state nanopore and the surface-charge density of the nanopore. For a polyelectrolyte driven by an external electric field, our numerical calculations show that the dynamics of polyelectrolyte translocation through a nanopore are mediated by the charge density σ of the nanopore surface. The result implies that the charge density can be an effective way to regulate the polyelectrolyte translocation. Moreover, for the first time results indicate that a threaded polyelectrolyte may be retracted from a nanopore, and that a nanometer-scale channel can act as nanopore tweezers, in the same way as optical or magnetic tweezers allow manipulation of single molecules.