On January 17, 2025, Professor ZHANG Zhen’s team at the Suzhou Institute for Advanced Research, University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), reported a solid-state proton gating membrane with an ultrahigh gating ratio of 5,740, surpassing existing technologies. The study was published in Nature Communications.

Biological ion channels exhibit strong gating effects due to their zero-current closed state. However, artificial nanochannels often demonstrate weaker gating capabilities because larger nanopores cannot fully block ion transport when in a closed state. In this study, the researchers designed and synthesized a solid-state membrane based on two-dimensional hydrogen-bonded organic frameworks (HOFs), achieving high-performance proton gating regulated by ambient humidity. Unlike traditional ion blocking/activation effects, this gating mechanism functions by switching proton transport pathways.

Overview of the high-performance solid-state proton gating membranes.(Image from Prof. ZHANG’s team)

Density functional theory (DFT) calculations revealed that the reversible formation and disruption of water bridges induced by humidity within the framework facilitated the transition of proton transport from site-to-site hopping to the Grotthuss mechanism. To further enhance performance, the researchers incorporated bacterial cellulose, improving the adsorption and desorption of water clusters. This ultimately enabled the membrane to achieve an unprecedented proton gating ratio of 5,740, far exceeding the capabilities of current solid-state gating devices.

Moreover, the membrane operates entirely on solid-state principles, ensuring broad applicability in environmental monitoring, human health sensing, and beyond.

This study offers new insights into the design of high-efficiency proton gating systems, paving the way for next-generation biomimetic ion transport technologies.

Paper link: https://www.nature.com/articles/s41467-025-56228-8

(Written by CHEN Yehong, Edited by ZHAO Zheqian, USTC News Center)