Polymer Translocation Through a Long Nanopore

TL;DR

This paper presents a theoretical model analyzing how nanopore length and diameter influence polymer translocation dynamics, revealing two regimes based on polymer size relative to pore length, consistent with experimental observations.

Contribution

The study introduces a model explicitly accounting for nanopore length and diameter effects on polymer translocation, highlighting the importance of pore length in different translocation regimes.

Findings

Translocation velocity is nearly constant for polymers larger than the pore length.

Velocity increases as polymer size decreases for smaller polymers.

Model predictions align with experimental data.

Abstract

Polymer translocation through a nanopore in a membrane investigated theoretically. Recent experiments on voltage-driven DNA and RNA translocations through a nanopore indicate that the size and geometry of the pore are important factors in polymer dynamics. A theoretical approach is presented which explicitly takes into account the effect of the nanopore length and diameter for polymer motion across the membrane. It is shown that the length of the pore is crucial for polymer translocation dynamics. The present model predicts that for realistic conditions (long nanopores and large external fields) there are two regimes of translocation depending on polymer size: for polymer chains larger than the pore length, the velocity of translocation is nearly constant, while for polymer chains smaller than the pore length the velocity increases with decreasing polymer size. These results agree with experimental data.