1. Division of Molecular Imaging and Photonics
2. Department of Chemistry
3. KU Leuven
4. 3001 Leuven
5. Belgium
6. Laboratory of Solid State Physics and Magnetism
7. Department of Physics and Astronomy
8. Centre for Surface Chemistry and Catalysis
9. Department of Microbial and Molecular Systems
10. Nano-Science Center
11. University of Copenhagen
12. 2100 Copenhagen
13. Denmark