1. Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland
2. Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, 08193 Barcelona, Catalonia, Spain
3. Department of Physics and Astronomy “Ettore Majorana”, University of Catania and CNR-IMM, Via S. Sofia 64, 95123 Catania, Italy
4. Electron Spectroscopy and Nanoscopy, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
5. Laboratory for Particles-Biology Interactions, Department of Materials Meet Life, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
6. Nanoparticle Systems Engineering Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
7. ICREA, 08010 Barcelona, Catalonia, Spain
8. LumiLab, Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, 9000 Ghent, Belgium