Dehydration as a Universal Mechanism for Ion Selectivity in Graphene and Other Atomically Thin Pores

Published

July 5, 2017

Author(s)

Subin Sahu, Massimiliano Di Ventra, Michael P. Zwolak

Abstract

Ion channels play a critical role in regulating cell behavior and in electrical signaling. In these settings, polar and charged functional groups -- as well as protein response -- give rise to ion selective transport, allowing the channels to perform specific tasks in the operation of cells. According to recent experiments, graphene nanopores can have both weak to strong selectivity, the origin of which is unclear. Here, we establish an alternative, novel mechanism for selectivity: Dehydration -- the most fundamental physical process in ion transport -- yields selective pores without the presence of charges or structural changes of the pore. This fundamental mechanism -- one that depends only on the geometry and hydration -- is the starting point for selectivity for all channels and pores. Its likely detection in graphene pores resolves the conflicting selectivity results, as well as opens up a new paradigm for engineering molecular/ionic selectivity in filtration and other applications.

Citation

Nano Letters

Volume

17

Issue

8

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.nanolett.7b01399

Keywords

Ion transport, nanofluidics, computational nanotechnology

Nanofluidics

Citation

Sahu, S. , Di, M. and Zwolak, M. (2017), Dehydration as a Universal Mechanism for Ion Selectivity in Graphene and Other Atomically Thin Pores, Nano Letters, [online], https://doi.org/10.1021/acs.nanolett.7b01399 (Accessed May 8, 2021)