Nanoarray-Surfaces by Reconstitution of the Porin MspA into Stabilized Long-Chain-Lipid-Monolayers at a Gold-Surface

• Published in: Electroanalysis (New York, N.Y.) N.Y.), 2006-10, Vol.18 (19-20), p.1859-1870
• Main Authors: Wörner, Michael, Niebler, Sandra, Gogritchiani, Eliso, Egner, Nicole, Braun, André M., Niederweis, Michael, Bossmann, Stefan H.
• Format: Article
• Language: English
• Subjects: Cu-nanoparticles; CV (cyclic voltammetry); EIS (electrochemical impedance spectroscopy); MspA (porin A from M. smegmatis); SAM (self-assembled monolayer)
• ISSN: 1040-0397; 1521-4109
• DOI: 10.1002/elan.200603636

We have reconstituted the channel porin MspA from M. smegmatis on a gold electrode into a long‐chain lipid monolayer resembling a biological membrane. The tailored deposition of the self‐assembled monolayer (SAM) on gold was achieved by employing electrochemically initiated generation of thiyl‐radicals from organic thiosulfates (Bunte‐Salts), which then adsorb onto the gold's surface. At surface coverage of the lipids of approximately 80%, MspA reconstituted efficiently from the aqueous buffer into the SAM. The combination of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), reflection electron microscopy (REM) and the formation of copper(0)‐nanoparticles from copper(II)‐ions inside the MspA‐channels proved that MspA forms SAM‐spanning ion channels on gold, keeping the electrode (surface) accessible through the pores.