Resonance-Mode Electrochemical Impedance Measurements of Silicon Dioxide Supported Lipid Bilayer Formation and Ion Channel Mediated Charge Transport
| Autor: | Julia Hedlund, Hans Elwing, Angelika Kunze, Magnus Brändén, Olof Andersson, Anders Lundgren, Fredrik Höök |
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| Rok vydání: | 2011 |
| Předmět: |
Ion Transport
Silicon dioxide Bilayer Lipid Bilayers Gramicidin technology industry and agriculture Analytical chemistry Self-assembled monolayer Silicon Dioxide Ion Channels Analytical Chemistry Dielectric spectroscopy chemistry.chemical_compound chemistry Dielectric Spectroscopy Monolayer Phosphatidylcholines lipids (amino acids peptides and proteins) Lipid bilayer POPC |
| Zdroj: | Analytical Chemistry. 83:7800-7806 |
| ISSN: | 1520-6882 0003-2700 |
| Popis: | A single-chip electrochemical method based on impedance measurements in resonance mode has been employed to study lipid monolayer and bilayer formation on hydrophobic alkanethiolate and SiO(2) substrates, respectively. The processes were monitored by temporally resolving changes in interfacial capacitance and resistance, revealing information about the rate of formation, coverage, and defect density (quality) of the layers at saturation. The resonance-based impedance measurements were shown to reveal significant differences in the layer formation process of bilayers made from (i) positively charged lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine (POEPC), (ii) neutral lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) on SiO(2), and (iii) monolayers made from POEPC on hydrophobic alkanethiolate substrates. The observed responses were represented with an equivalent circuit, suggesting that the differences primarily originate from the presence of a conductive aqueous layer between the lipid bilayers and the SiO(2). In addition, by adding the ion channel gramicidin D to bilayers supported on SiO(2), channel-mediated charge transport could be measured with high sensitivity (resolution around 1 pA). |
| Databáze: | OpenAIRE |
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