1. Istituto per la Microeletttronica e Microsistemi—Consiglio Nazionale delle Ricerche, VIII Strada Z.I., 5, 95121 Catania, Italy
2. Department of Chemical Sciences, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy
3. URT “LabSens of Beyond Nano” of the Department of Physical Sciences and Technologies of Matter, National Research Council (CNR-DSFTM-ME), Viale Ferdinando Stagno D’Alcontres 31, 98166 Messina, Italy
4. Department of Medical, Surgical Sciences and Advanced Technologies, University of Catania, Via S. Sofia 78, 95123 Catania, Italy