1. IFAC-CNR; Institute of Applied Physics “Nello Carrara,”; National Research Council; Via Madonna del Piano 10 I-50019 Sesto Fiorentino Italy
2. IPCF-CNR; Institute for Chemical and Physical Processes; National Research Council; Viale F. Stagno D'Alcontres 37 I-98158 Messina Italy
3. Department of Experimental and Clinical Biomedical Sciences; University of Florence; Viale Morgagni 50 I-50134 Firenze Italy
4. Department of MIFT; University of Messina; Viale F. Stagno d'Alcontres 31 I-98166 Messina Italy
5. Department of Physics; University of Genoa; Via Dodecaneso 33 I-16146 Genova Italy
6. Department of Chemistry and Industrial Chemistry; University of Genoa; Via Dodecaneso 31 I-16146 Genova Italy