1. Laboratory for Electrophysiology and Biotechnology, Department of Physiology, University of Freiburg, Hermann-Herder-Strasse 7, 79104 Freiburg, Germany
2. Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
3. IFR Jean Roche, Secteur Nord de la Faculté de Médecine de Marseille, Marseille 13916, France
4. Freiburg Materials Research Centre (FMF), University of Freiburg, Stefan-Meier-Strasse 21, 79104 Freiburg, Germany