1. Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, S.S. 554 Bivio per Sestu, 09042 Monserrato (CA), Italy
2. Department of Chemical Science and Technologies, University of Rome “Tor Vergata”, 00133 Rome, Italy
3. Department of Electronic Engineering, University of Rome “Tor Vergata”, 00133 Rome, Italy