Detection of supported lipid bilayers using their electric charge.
We describe an electronic detection method for charged lipid bilayers supported on a Si 3N 4/SiO 2/Si substrate. The flat-band voltage was used to monitor the charge of the bilayers. We show that the flat-band voltage varies with lipid adsorption depending on the polarity and mole ratio of the charged lipids, the salt concentration, and the surface coverage. Cationic and anionic bilayers produced a decrease and an increase in the flat-band voltage, respectively. The voltage change increased as the percentage of charged lipid components was elevated in the planar bilayers with full surface coverage. In addition, the voltage variation increased when the salt concentration was decreased or when the surface coverage of planar bilayer patches was increased. These results demonstrate that charged bilayers can be detected from the field effect that they exert on a solid support.
Kataoka-Hamai
Chiho
C
Biomaterials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Inoue
Hiromi
H
Miyahara
Yuji
Y
D000838:Anions; D001703:Biophysics / Q000379:methods; D002412:Cations; D025802:Electric Capacitance; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D005229:Fatty Acids, Monounsaturated / Q000737:chemistry; D008051:Lipid Bilayers; D008055:Lipids; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D015233:Models, Statistical; D010713:Phosphatidylcholines / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012492:Salts; D013499:Surface Properties
D000838:Anions; D002412:Cations; D005229:Fatty Acids, Monounsaturated; D008051:Lipid Bilayers; D008055:Lipids; D010713:Phosphatidylcholines; D000644:Quaternary Ammonium Compounds; D012492:Salts; C017251:1,2-oleoylphosphatidylcholine; C070046:1,2-dioleoyloxy-3-(trimethylammonium)propane