Related Experiment Video
Updated: May 23, 2025
Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution
Published on: August 16, 2016
Regulate Ion Transport in Subnanochannel Membranes by Ion-Pairing
Rongming Xu1,2, Hang Yu1,2, Jiachun Ren1,2
1State Key Laboratory of Water Pollution Control and Green Resource Recycling, School of Environment, Nanjing University, Nanjing 210023, China.
None:
The ability of biological ion channels to respond to environmental stimuli, regulate ion permeation rates, and selectively transport specific ions is essential for sustaining physiological functions and holds immense potential for various practical applications. In this study, we report a highly selective ion separation membrane capable of responding to ionic stimuli, thereby regulating the permeation rate of the target ions. This membrane is constructed from two-dimensional MXene nanosheets functionalized with γ-poly(glutamic acid) (γ-PGA) molecules. Its biomimetic ion channel structure provides spatial confinements, as well as ion recognition and response sites. Remarkably, the membrane demonstrates the ability to respond to stimulus ions, achieving regulation of target ion permeation rates by over 2 orders of magnitude and achieving a K+/Mg2+ selectivity exceeding 10.3 Unlike traditional nanochannel membranes, where ion transport is predominantly driven by ion-channel interactions, this membrane operates through an ion-ion interaction-dominated mechanism. The introduction of stimulus ions dynamically alters ion-pair formation within the subnanochannels, thereby modulating the permeation rates of target ions. This study provides a fresh perspective on ion transport mechanisms in nanoconfined environments, reflecting conditions closer to those in real-world systems. It underscores the pivotal role of ion-ion interactions in regulating ion transport and offers valuable insights into the design of next-generation ion separation membranes with tailored responsiveness.
Related Concept Videos
01:17Pore Transport and Ion-Pair Transport
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
01:19Ion Channels
Ion channels are specialized integral membrane proteins on the plasma membrane that allow...
01:21Electrochemical Gradient and Channel Proteins: An Overview
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to...
01:24Non-gated Ion Channels
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism....
01:19Membrane Asymmetry Regulating Transporters
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
01:44The Significance of Membrane Transport
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...