Electric Field Modulation of the Membrane Potential in Solid-State Ion Channels

Guan, Weihua; Reed, Mark A.

doi:10.1021/nl303820a

Cited by 50 publications

(56 citation statements)

References 32 publications

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“…13 Moreover, another pioneering work investigated the ionic response to ac fields. 14 From another perspective, there are many possibilities for constructing narrow channels to obtain various nonlinear ionic transport characteristics. Despite a long history, 15−18 however, the relation between the time and spatial scales of the electrical response of ionic solutions at the nanoscale remains unsolved.…”

Section: Introductionmentioning

confidence: 99%

Nonequilibrium Ionic Response of Biased Mechanically Controllable Break Junction (MCBJ) Electrodes

et al. 2014

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Novel experimental techniques allow for the manipulation and interrogation of biomolecules between metallic probes immersed in micro/nanofluidic channels. The behavior of ions in response to applied fields is a major issue in the use of these techniques in sensing applications. Here, we experimentally and theoretically elucidate the behavior of background currents in these systems. These large currents have a slowly decaying transient response, as well as noise that increases with ionic concentration. Using mechanically controllable break junctions (MCBJ), we study the ionic response in nanogaps with widths ranging from a few nanometers to millimeters. Moreover, we obtain an expression for the ionic current by solving time-dependent Nernst–Planck and Poisson equations. This expression shows that after turning on an applied voltage, ions rapidly respond to the strong fields near the electrode surface, screening the field in the process. Ions subsequently translocate in the weak electric field and slowly relax within the diffusion layer. Our theoretical results help to explain the short- and long-time behavior of the ionic response found in experiments, as well as the various length scales involved.

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Section: Introductionmentioning

confidence: 99%

Nonequilibrium Ionic Response of Biased Mechanically Controllable Break Junction (MCBJ) Electrodes

et al. 2014

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“…The membrane transport experiments in [9] revealed that that the fluxes of anionic and cationic permeate species change as a function of applied potential. The modulation of membrane potential by the external electric field in solid-state channels was also demonstrated in [10], while a significant increase of ionic conductivity in nanopores and nanochannels due to application of a prescribed potential to their conductive surface was reported in [11][12][13].…”

Section: Introductionmentioning

confidence: 89%

Modelling of Electrochemically Switchable Ion Transport in Nanoporous Membranes with Conductive Surface

Ryzhkov

Vyatkin

Медведева

2019

Journal of Siberian Federal University. Mathematics &Amp; Physics

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The impact of potential applied to the conductive surface of nanoporous membrane on the membrane potential at zero current is investigated theoretically on the basis of two–dimensional Space–charge model. The membrane separates two reservoirs with different salt concentrations. It is shown that the variation of applied potential from negative to positive values results in the continuous change of membrane selectivity from cation to anion. For equal ion diffusion coefficients, the dependence of membrane potential on the applied potential is an odd function, while for different ion diffusion coefficients it is shifted along the applied potential axis due to contribution of diffusion potential enhanced by the induced charge effect. The decrease of pore radius results in the increase of ionic selectivity and steep transition between cation– selective and anion–selective states when the applied potential is changing

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“…(14c). The shooting method is used to solve the problem by integrating (14) from z = 0 to z = 1 and matching the hydrostatic pressure, salt concentration and pH in the reservoir connected to the pore exit.…”

Section: Theoretical Modelmentioning

confidence: 99%

Theory of Ion and Water Transport in Electron-Conducting Membrane Pores with p H-Dependent Chemical Charge

Zhang¹,

Biesheuvel²,

Ryzhkov

2019

Phys. Rev. Applied

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In this work, we develop an extended uniform potential (UP) model for a membrane nanopore by including two different charging mechanisms of the pore walls, namely by electronic charge and by chemical charge. These two charging mechanisms will generally occur in polymeric membranes with conducting agents, or membranes made of conducting materials like carbon nanotubes with surface ionizable groups. The electronic charge redistributes along the pore in response to the gradient of electric potential in the pore, while the chemical charge depends on the local pH via a Langmuir-type isotherm. The extended UP model shows good agreement with experimental data for membrane potential measured at zero current condition. When both types of charge are present, the ratio of the electronic charge to the chemical charge can be characterized by the dimensionless number of surface groups and the dimensionless capacitance of the dielectric Stern layer. The performance of the membrane pore in converting osmotic energy from a salt concentration difference into electrical power can be improved by tuning the electronic charge.

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Electric Field Modulation of the Membrane Potential in Solid-State Ion Channels

Cited by 50 publications

References 32 publications

Nonequilibrium Ionic Response of Biased Mechanically Controllable Break Junction (MCBJ) Electrodes

Nonequilibrium Ionic Response of Biased Mechanically Controllable Break Junction (MCBJ) Electrodes

Modelling of Electrochemically Switchable Ion Transport in Nanoporous Membranes with Conductive Surface

Theory of Ion and Water Transport in Electron-Conducting Membrane Pores with p H-Dependent Chemical Charge

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