Resonance-Mode Electrochemical Impedance Measurements of Silicon Dioxide Supported Lipid Bilayer Formation and Ion Channel Mediated Charge Transport
Artikel i vetenskaplig tidskrift, 2011

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).

chip

gramicidin

self-assembled monolayers

spectroscopy

alkanethiol

gold

biomimetic membranes

adsorption

protein

biosensor

Författare

A. Lundgren

Göteborgs universitet

J. Hedlund

Stena Center

O. Andersson

Stena Center

Magnus Brändén

Chalmers, Teknisk fysik, Biologisk fysik

Angelika Kunze

Chalmers, Teknisk fysik, Biologisk fysik

H. Elwing

Göteborgs universitet

Fredrik Höök

Chalmers, Teknisk fysik, Biologisk fysik

Analytical Chemistry

0003-2700 (ISSN) 1520-6882 (eISSN)

Vol. 83 7800-7806

Ämneskategorier

Kemi

DOI

10.1021/ac201273t