Related Experiment Video
Updated: Jul 11, 2026
19:56
Introduction to Solid Supported Membrane Based Electrophysiology
Published on: May 11, 2013
An electrochemical gate based on a stimuli-responsive membrane associated with an electrode surface
Ihor Tokarev1, Maxim Orlov, Evgeny Katz
1Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699-5810, USA.
The Journal of Physical Chemistry. B
|October 6, 2007
Summary
A novel electrochemical gate uses a cholesterol-responsive membrane to control ion flow. This system, based on hydrogen bonding, allows reversible "on-off" switching of electrochemical signals, paving the way for advanced biosensors.
Area of Science:
- Electrochemistry
- Materials Science
- Biochemistry
Background:
- Electrochemical gates are crucial for controlling signal transduction in biosensing applications.
- Chemical signal-responsive membranes offer a pathway to create tunable electrochemical interfaces.
- Cholesterol detection and modulation are important in various biological and medical contexts.
Purpose of the Study:
- To develop and characterize a novel electrochemical gate based on a chemical signal-responsive membrane.
- To investigate the reversible switching of electrochemical processes triggered by cholesterol.
- To explore the tuneable control of electrochemical reactions by varying cholesterol concentration.
Main Methods:
- Assembly of a polyelectrolyte gel membrane on a gold electrode.
- Utilizing hydrogen bonding between cholesterol and the polymer backbone to induce membrane swelling/deswelling.
- Employing cyclic voltammetry and Faradaic impedance spectroscopy to monitor electrochemical activity.
- Employing atomic force microscopy to characterize membrane morphology changes.
Main Results:
- The polyelectrolyte gel membrane exhibited reversible swelling and channel closure upon cholesterol binding.
- The electrochemical response of a redox probe ([Fe(CN)(6)](3-/4-)) was reversibly switched 'on-off' by cholesterol addition and removal.
- The degree of channel closure, and thus the electrochemical signal, was tuneable by varying cholesterol concentration.
- Characterization confirmed that cholesterol concentration dictates the extent of pore opening and closing.
Conclusions:
- A switchable and tuneable electrochemical gate responsive to cholesterol has been successfully demonstrated.
- The system's operation relies on cholesterol-induced changes in membrane structure and ion permeability.
- This chemically controlled electrochemical gate holds potential for integration into future biochemical systems and logic operations.
Related Concept Videos
01:15Potentiometry: Membrane Electrodes
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...
01:21Electrochemical Gradient and Channel Proteins: An Overview
An electrochemical gradient is a fundamental concept in biology and chemistry. It regulates the movement of ions across cell membranes. This movement is influenced by two factors:
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 the...
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 the...
01:12Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
01:12Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
01:21G-Protein Gated Ion Channels
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Sensory organs,...
01:28Types of Receptors: Cell Surface Receptors
Cell-surface receptors, also known as transmembrane receptors, are cell surface, membrane-anchored (integral) proteins that bind to external ligand molecules. This type of receptor spans the plasma membrane and performs signal transduction, converting an extracellular signal into an intracellular signal. Ligands that interact with cell-surface receptors do not have to enter the cell that they affect. Cell-surface receptors are also called cell-specific proteins or markers because they are...