1. Laboratoire de Nanotechnologie et d’Instrumentation Optique LNIO−CNRS UMR 6279, Université de Technologie de Troyes, Troyes, France
2. Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
3. CNRS-CEA, IRAMIS, SPAM, Laboratoire Francis Perrin, URA2453, 91191 Gif-sur-Yvette, France
4. Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States