This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.107.122887v1 94/12/4711    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Jeuken, L. J. C. PubMed PubMed Citation Articles by Jeuken, L. J. C.

AFM Study on the Electric-Field Effects on Supported Bilayer Lipid Membranes

Institute of Membrane and Systems Biology, University of Leeds, Leeds, United Kingdom

Correspondence: Address reprint requests to Lars J. C. Jeuken, Tel.: 44-0-113-343-3829; E-mail: l.j.c.jeuken{at}leeds.ac.uk.

Electric-field induced changes in structure and conductivity of supported bilayer lipid membranes (SLM) have been studied at submicroscopic resolution using atomic force microscopy and electrochemical impedance spectroscopy. The SLMs are formed on gold surfaces modified with mixed self-assembled monolayers of a cholesterol-tether and 6-mercaptohexanol. At applied potentials of –0.25 V versus standard hydrogen electrode, the conductance of the SLM increases and membrane areas of <150 nm in size are found to elevate from the surface up to 15 nm in height. To estimate the electric field experienced by the lipid membrane, electrowetting has been used to determine the point of zero charge of a 6-mercaptohexanol-modified surface (0.19 ± 0.13 V versus standard hydrogen electrode). The effects of electric fields on the structure and conductance of supported membranes are discussed.