Predicting optimal parameters for ion transport through nanopores and biological channels*

Understanding, predicting and optimising ionic transport properties of pores on an atomic scale remains a critical challenge to, nanotechnology and biophysics [1]. In general, pores are designed to fulfil two criteria: conduction of ions at a high rate; and the selectivity amongst ionic species. We have derived a statistical and linear response theory that calculates the occupancy and conductivity of nanopores for given parameters including: pore geometry and charge; type of competing ionic species; and bulk concentration [2]. We find resonant conduction under known conditions, resulting in the coexistence of resonance for one species and suppression for the other and can predict optimal parameters required to produce the desired function. Examples of applications to biological channels and nanopores will be discussed.

[1] Hille, B., 2001, 3rd ed. Sinauer Ass., Sunderland, M.A. & Wang. L., et. al., Nat. nanotechnology, 2017. [2] Gibby, W.A.T., et. al., "Statistical theory of mixed-valence selectivity in biological ion channels", ICNF preprint, 2019. & Gibby, W.A.T., et. al., "Theory and experiments on multi-ion permeation and selectivity in the NaChBac ion channel", FNL 18, 1940007 2019.