1. Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF); Karlsruhe Institute of Technology (KIT); Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
2. Department of Chemistry Doane University; 014 Boswell Ave Crete NE 68333 USA
3. Institute of Microstructure Technology (IMT); Karlsruhe Institute of Technology (KIT); Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
4. Institute of Organic Chemistry; Karlsruhe Institute of Technology (KIT); Fritz-Haber-Weg 6 76131 Karlsruhe Germany
5. Physical Institute and Center for Nanotechnology (CeNTech); University of Münster; Wilhelm-Klemm-Straße 10 48149 Münster Germany