An artificial sodium-selective subnanochannel

Jun Lu; Gengping Jiang; Huacheng Zhang; Binbin Qian; Haijin Zhu; Qinfen Gu; Yuan Yan; Jefferson Zhe Liu; Benny D Freeman; Lei Jiang; Huanting Wang

doi:10.1126/sciadv.abq1369

An artificial sodium-selective subnanochannel

Sci Adv. 2023 Jan 27;9(4):eabq1369. doi: 10.1126/sciadv.abq1369. Epub 2023 Jan 27.

Authors

Jun Lu¹, Gengping Jiang², Huacheng Zhang³, Binbin Qian¹, Haijin Zhu⁴, Qinfen Gu⁵, Yuan Yan⁶, Jefferson Zhe Liu⁶, Benny D Freeman⁷, Lei Jiang¹, Huanting Wang¹

Affiliations

¹ Department of Chemical and Biological Engineering, Monash University, Clayton, Victoria 3800, Australia.
² Department of Applied Physics, College of Science, Wuhan University of Science and Technology, Wuhan 430072, China.
³ Chemical and Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria 3000, Australia.
⁴ Institute for Frontier Materials, Deakin University Waurn Ponds Campus, Geelong, Victoria 3216, Australia.
⁵ ANSTO, Australian Synchrotron, 800 Blackburn Rd., Clayton, Victoria 3168, Australia.
⁶ Department of Mechanical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
⁷ Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA.

Abstract

Single-ion selectivity with high precision has long been pursued for fundamental bioinspired engineering and applications such as in ion separation and energy conversion. However, it remains a challenge to develop artificial ion channels to achieve single-ion selectivity comparable to their biological analogs, especially for high Na⁺/K⁺ selectivity. Here, we report an artificial sodium channel by subnanoconfinement of 4'-aminobenzo-15-crown-5 ethers (15C5s) into ~6-Å-sized metal-organic framework subnanochannel (MOFSNC). The resulting 15C5-MOFSNC shows an unprecedented Na⁺/K⁺ selectivity of tens to 10² and Na⁺/Li⁺ selectivity of 10³ under multicomponent permeation conditions, comparable to biological sodium channels. A co-ion-responsive single-file transport mechanism in 15C-MOFSNC is proposed for the preferential transport of Na⁺ over K⁺ due to the synergetic effects of size exclusion, charge selectivity, local hydrophobicity, and preferential binding with functional groups. This study provides an alternative strategy for developing potential single-ion selective channels and membranes for many applications.