Effect of Electro-Diffusion Current Flow on Electrostatic Screening in Aqueous Pores

TL;DR

This study uses numerical simulations to show that electro-diffusion currents in aqueous pores reduce electrostatic screening of bio-molecules, leading to longer-range interactions, which could enhance bio-molecule charge sensing techniques.

Contribution

It demonstrates how external biases and electrodiffusion currents alter electrostatic screening in synthetic pores, diverging from classical equilibrium models.

Findings

Electrodiffusion currents partially screen bio-molecule charges.

Screening behavior differs from classical Debye-Huckel theory under bias.

Potential for improved bio-molecule charge sensing applications.

Abstract

A numerical study within the framework of the Poisson-Nernst-Planck equations is conducted to investigate electrostatic screening of charged bio-molecules within synthetic pores having diameters of at least 10 Debye lengths. We show that with external biases, the bio-molecule charge is only partially screened due to the presence of electrodiffusion current flow. This is considerably different from the equilibrium Debye-Huckel screening behavior and will result in long-range electrostatic interactions. The potential application to direct bio-molecule charge sensing is also discussed.