Prospects of Observing Ionic Coulomb Blockade in Artificial Ion Confinements

Abstract

Nanofluidics encompasses a wide range of advanced approaches to study charge and mass transport at the nanoscale. Modern technologies allow us to develop and improve artificial nanofluidic platforms that confine ions in a way similar to single-ion channels in living cells. Therefore, nanofluidic platforms show great potential to act as a test field for theoretical models. This review aims to highlight ionic Coulomb blockade (ICB)—an effect that is proposed to be the key player of ion channel selectivity, which is based upon electrostatic exclusion limiting ion transport. Thus, in this perspective, we focus on the most promising approaches that have been reported on the subject. We consider ion confinements of various dimensionalities and highlight the most recent advancements in the field. Furthermore, we concentrate on the most critical obstacles associated with these studies and suggest possible solutions to advance the field further.

Surface charge density governs the ionic current rectification direction in asymmetric graphene oxide channels

“…The ultralow flux of ions in narrower channels with higher σ corresponds to Coulomb blockade induced by electrostatic interactions, and this phenomenon has in fact been predicted for low-capacitance, water-filled, charged ion channels. 50,51…”

“…The ultralow flux of ions in narrower channels with higher s corresponds to Coulomb blockade induced by electrostatic interactions, and this phenomenon has in fact been predicted for low-capacitance, waterfilled, charged ion channels. 50,51 As we have discussed for Fig. 2, the present ion selectivity should be codetermined by both the channel geometry and electrostatic interactions.…”

“…For this reason, the ion enrichment inside the channel results in the formation of solid ion clusters under ÀE, while almost without free ions that leads to the Coulomb blockade. 50,51 This effect weakens the ionic current and results in ICR reversion.…”

Stress induced delamination of suspended MoS2 in aqueous environments

“…20,30,47 Although the large modulation of ionic transport due to partial delamination is similar to the case of pressure induced nanoparticle blockages 47 and could be used to produce more robust mechanical pressure sensors, it is still far away from true mechanosensitivity where ion transport is modulated by mechanical stress directly modulating the energy barriers for single ion translocations. 46,48 Our approach allows a better understanding of measurements with supported 2D materials, i.e. avoiding misinterpreting the measured data and could be used to probe how the electrical field and fluid flow at the nanoscale would influence membrane adhesion.…”

Introduction to the Physics of Ionic Conduction in Narrow Biological and Artificial Channels

“…The work by A. Chernev et al [ 13 ] reviews the most promising approaches to the fabrication of artificial nanofluidic devices capable of reproducing the properties of single ion channels. It is shown that modern technologies have great potential in allowing one to test various theoretical models of ion channels.…”