1. Division of Materials Science and Engineering, CSIRO, Private Bag 33, Clayton South MDC, Victoria 3169, Australia
2. Associazione CIVEN−Nano Fabrication Facility, Via delle Industrie 9, 30175 Venezia, Italy
3. Laboratorio di Scienza dei Materiali e Nanotecnologie (LMNT), CR-INSTM, Università di Sassari, Palazzo Pou Salid Piazza Duomo 6, 07041 Alghero SS, Italy
4. Centre for Micro-Photonics and CUDOS, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
5. Porto Conte Ricerche s.r.l., S.P. 55, km 8,400, 07041 Alghero SS, Italy
6. CNR-IOM, Laboratorio TASC, S.S. 14, Km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
7. Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria