Controlling ionic current through a nanopore by tuning pH: a local equilibrium Monte Carlo study

The purpose of this work is to create a model of a nanofluidic transistor which is able to mimic the effects of pH on nanopore conductance. The pH of the electrolyte is an experimentally controllable parameter through which the charge pattern can be tuned: pH affects the ratio of the protonated/depr...

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Bibliographic Details
Published inMolecular physics Vol. 117; no. 20; pp. 2793 - 2801
Main Authors Fertig, Dávid, Valiskó, Mónika, Boda, Dezső
Format Journal Article
LanguageEnglish
Published Abingdon Taylor & Francis 18.10.2019
Taylor & Francis Ltd
Subjects
Bipolar transistors
Computer simulation
Depletion
Fluidics
Functional groups
Monte Carlo
Nanofluids
Nanopores
Nernst-Planck
pH control
Porosity
Resistance
Semiconductor devices
Stability
Surface charge
transistor
Transistors
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Summary:The purpose of this work is to create a model of a nanofluidic transistor which is able to mimic the effects of pH on nanopore conductance. The pH of the electrolyte is an experimentally controllable parameter through which the charge pattern can be tuned: pH affects the ratio of the protonated/deprotonated forms of the functional groups anchored to the surface of the nanopore (for example, amino and carboxyl groups). Thus, the behaviour of the bipolar transistor changes as it becomes ion selective in acidic/basic environments. We relate the surface charge to pH and perform particle simulations (Local Equilibrium Monte Carlo) with different nanopore geometries (cylindrical and double conical). The simulations form a self consistent system with the Nernst-Planck equation with which we compute ionic flux. We discuss the mechanism behind pH-control of ionic current: formation of depletion zones.
ISSN:0026-8976
1362-3028
DOI:10.1080/00268976.2018.1554194