1. Institut
Lumière Matière, UMR5306 Université Claude Bernard
Lyon1-CNRS, Université de Lyon 69622 Villeurbanne
cedex, France
2. Group
of Applied Physics (GAP) Biophotonics, Université de Genève, Chemin
de Pinchat 22, CH-1211 Geneva, Switzerland
3. Department
of Chemistry, University of Basel, Klingelbergstr 80, CH-4056 Basel, Switzerland