Enhanced polymer capture speed and extended translocation time in pressure-solvation traps

Abstract

The efficiency of nanopore-based biosequencing techniques requires fast anionic polymer capture by like-charged pores followed by a prolonged translocation process. We show that this condition can be achieved by setting a pressure-solvation trap. Polyvalent cation addition to the KCl solution triggers the like-charge polymer-pore attraction. The attraction speeds-up the pressure-driven polymer capture but also traps the molecule at the pore exit, reducing the polymer capture time and extending the polymer escape time by several orders of magnitude. By direct comparison with translocation experiments [D. P. Hoogerheide et al., ACS Nano 8, 7384 (2014)], we characterize as well the electrohydrodynamics of polymers transport in pressure-voltage traps. We derive scaling laws that can accurately reproduce the pressure dependence of the experimentally measured polymer translocation velocity and time. We also find that during polymer capture, the electrostatic barrier on the translocating molecule slows down the liquid flow. This prediction identifies the streaming current measurement as a potential way to probe electrostatic polymer-pore interactions.

References in corpus (10)

• Nonequilibrium dynamics of polymer translocation and straightening
• Translocation frequency of double-stranded DNA through a solid-state nanopore
• Effective charge and free energy of DNA inside an ion channel
• Self-energy limited ion transport in sub-nanometer channels
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• Multivalent cation induced attraction of anionic polymers by like-charged pores

Cited by in corpus (2)

• Dielectric manipulation of polymer translocation dynamics in engineered membrane nanopores
• Theoretical modeling of polymer translocation: From the electrohydrodynamics of short polymers to the fluctuating long polymers