Electric-field-driven polymer entry into asymmetric nanoscale channels

Abstract

The electric-field-driven entry process of flexible charged polymers such as single stranded DNA (ssDNA) into asymmetric nanoscale channels such as alpha-hemolysin protein channel is studied theoretically and using molecular dynamics simulations. Dependence of the height of the free-energy barrier on the polymer length, the strength of the applied electric field and the channel entrance geometry is investigated. It is shown that the squeezing effect of the driving field on the polymer and the lateral confinement of the polymer before its entry to the channel crucially affect the barrier height and its dependence on the system parameters. The attempt frequency of the polymer for passing the channel is also discussed. Our theoretical and simulation results support each other and describe related data sets of polymer translocation experiments through the alpha-hemolysin protein channel reasonably well.

References in corpus (5)

• Physical approaches to DNA sequencing and detection
• Scaling theory of DNA confined in nanochannels and nanoslits
• Effective charge and free energy of DNA inside an ion channel
• Self-energy limited ion transport in sub-nanometer channels
• Theory of DNA translocation through narrow ion channels and nanopores with charged walls