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Issue 17, 2009
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Impedance analysis of gramicidin D in pore-suspending membranes

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Porous alumina substrates with a pore diameter of 60 nm were functionalized with cholesterylpolyethylenoxy thiol (CPEO3) chemisorbed on gold, which is a prerequisite for the formation of pore-suspending membranes obtained from spreading of large unilamellar vesicles with a mean diameter of 730 nm. By means of vesicle fusion, a large number of gramicidin D ion channels, selective for monovalent cations, was successfully reconstituted into these pore-suspending membranes as probed by impedance spectroscopy. An electrical equivalent circuit was developed to fully describe the electrical properties of the gramicidin D-doped membrane system, which allowed us not only to extract the membrane resistance but also the mass transport in bulk solution as a function of the monovalent cation concentration in solution. Blocking of channel activity was demonstrated by the addition of Ca2+ ions verifying the reconstitution of fully functional peptides.

Graphical abstract: Impedance analysis of gramicidin D in pore-suspending membranes

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The article was received on 26 Jan 2009, accepted on 18 May 2009 and first published on 30 Jun 2009

Article type: Paper
DOI: 10.1039/B901683J
Soft Matter, 2009,5, 3347-3353

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    Impedance analysis of gramicidin D in pore-suspending membranes

    E. K. Schmitt, C. Weichbrodt and C. Steinem, Soft Matter, 2009, 5, 3347
    DOI: 10.1039/B901683J

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