Nonlinear Biomedical Physics

Department of Physics

Ionic Coulomb blockade in biological ion channels

We are developing novel ionic Coulomb blockade model of permeation and selectivity in biological ion channels. That is a large EPSRC-funded multi-disciplinary and multi-university Project carried out in 2015-2018.

Lancaster University
Warwick University

Biological ion channels are protein nanotubes that embedded in, and passing through, the bilipid membranes of cells. Physiologically, the ion channels are of crucial importance in that they allow ions to pass into and out of cells, fast and efficiently, though in a highly selective way.


The Ionic Coulomb blockade (ICB) phenomenon appears in low-capacitance electrodiffusion systems and arises from the discreteness of electrical charge, the strong electrostatic interaction, and an electrostatic exclusion principle. ICB provides a straightforward explanation of numerous observed and modelled conduction and valence selectivity phenomena, including the anomalous mole fraction effect and the calcium conduction bands.


ICB and resonant conduction are quite similar to electronic Coulomb blockade and resonant tunnelling in quantum dots. The same considerations may also be applicable to other kinds of channel, as well as to charged artificial nanopores.

Generic self-consistent electrostatic model of calcium ion channel: "charged hole in the wall", reproduce features or real ion channels. Resonant Calcium conduction occurs at optimal fixed charge value when diffusion is barrier-less. Coulomb blocade oscillation of Calcium conduction and occupancy presents fundamental electrostatic phenomenon.

Our central aim is to understand conduction and selectivity in biological ion channels and artificial nanopores, taking advantage of the insights afforded by the ICB, combined with the discreteness of the ions and their hydration shells.

The theoretical and numerical results are tested against earlier observations and new experimental measurements planned on mutation transformations in bacterial sodium ion channels.

Our detailed objectives are -

These challenging objectives are to be attained through coordinated, interdisciplinary, endeavour combining the expertise of the groups in Lancaster Physics (Nonlinear and Biomedical Physics, NBP), Lancaster Health and Medicine (Biomedical and Life Sciences, BLS), and the Centre for Scientific Computing in Warwick University, guided and advised by our long-term collaborator Bob Eisenberg in Chicago Rush University. The joint research is carried out under EPSRC-funded Project (grant No EP/M015831/1)"Ionic Coulomb blockade oscillations and the physical origins of permeation, selectivity, and their mutation transformations in biological ion channels" .

Recent publications

Online Presentations