1. Institute of Nanoscience and Nanotechnology, National Center for Scientific Research “Demokritos”, Agia Paraskevi, 15341 Athens, Greece
2. Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, Zografou, 15780 Athens, Greece
3. IAMAS Technologies Ltd., 128 City Road, London EC1V 2NX, UK