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Updated: Mar 5, 2026

Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution
Published on: August 16, 2016
Mimicking pH-Gated Ionic Channels by Polyelectrolyte Complex Confinement Inside a Single Nanopore.
Yixuan Zhao1, Jean-Marc Janot1, Emmanuel Balanzat2
1Institut Européen des Membranes, UMR5635 UM ENSM CNRS, Place Eugène Bataillon, 34095 Montpellier cedex 5, France.
Researchers developed a novel pH-gated nanopore using layer-by-layer assembly of polyethylenimine and chondroitin-4-sulfate (ChS). This artificial channel exhibits anion selectivity and pH-dependent gating, opening below pH 4-5.
Area of Science:
- Biomimetic Nanotechnology
- Materials Science
- Electrochemistry
Background:
- Biological ion channels inspire artificial nanopore design for stimuli-responsive applications.
- Layer-by-layer self-assembly offers a versatile method for creating functional nanomaterials.
- Understanding ion transport mechanisms is crucial for developing advanced sensing and separation technologies.
Purpose of the Study:
- To develop a novel pH-gated nanopore using polyethylenimine and chondroitin-4-sulfate (ChS) via layer-by-layer self-assembly.
- To investigate the ionic transport properties and pH-responsive behavior of the fabricated nanopore.
- To elucidate the structural and charge-based mechanisms underlying the nanopore's gating function.
Main Methods:
- Fabrication of nanopores using layer-by-layer self-assembly of polyethylenimine and chondroitin-4-sulfate.
- Real-time monitoring of nanopore functionalization.
- Single nanopore ionic transport measurements under varying pH and salt concentrations.
Main Results:
- The developed nanopore exhibits rapid functionalization and real-time monitoring capabilities.
- Selective transport of anions was observed.
- Distinct pH-gated properties were demonstrated, with the nanopore opening at pH below 4 or 5, dependent on salt concentration.
- These properties are attributed to pH-induced changes in ChS conformation and polyelectrolyte complex swelling.
Conclusions:
- A novel, rapidly assembled pH-gated nanopore was successfully created using polyethylenimine and chondroitin-4-sulfate.
- The nanopore demonstrates anion selectivity and pH-responsive gating, opening at acidic pH.
- The observed behavior is governed by the pH-dependent charge and conformational changes of chondroitin-4-sulfate within the polyelectrolyte complex.
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