1. School of Chemical Sciences and National Institute for Cellular, BiotechnologyDublin City University 9 Glasnevin, Dublin Ireland
2. ISOF-CNR Area della Ricerca di Bologna Via P. Gobetti 101 40129 Bologna Italy
3. Institute of Nanoscience and Nanotechnology, N.C.S.R. Demokritos Agia Paraskevi Attikis P.O. Box 60037, 15341 Athens Greece
4. Department of Physics, Chemistry and PharmacyUniversity of Southern Denmark Campusvej 55 5230 Odense M Denmark