1. Department of Physics, University of Calabria, Arcavata di Rende, 87036 Italy
2. CNR-Nanotec, c/o Department of Physics University Sapienza, 00185 Roma, Italy
3. European Synchrotron Radiation Facility, 38043 Grenoble, France
4. Department of Pharmacy and biotechnology, University Bologna, 40127 Bologna, Italy
5. INSERM U836, Grenoble Institute of Neuroscience, 38700 Grenoble, France
6. Institute for Photonics and Nanotechnologies - CNR, 00156 Roma Italy
7. Fondazione Santa Lucia, 00179 Roma, Italy
8. Department of Public Health and Infectious Diseases, University Sapienza, 00185 Roma, Italy