1. Metamaterials Unit, Faculty of Science, University of Malta, MSD 2080 Msida, Malta
2. Institute of Physics, University of Zielona Gora, ul. Szafrana 4a, 65-069 Zielona Gora, Poland
3. Centre for Molecular Medicine and Biobanking, University of Malta, MSD 2080 Msida, Malta
4. Department of Engineering, Faculty of Environment, Science and Economy, University of Exeter, North Park Road, Exeter EX4 4QF, UK
5. Department of Chemistry, University of Malta, MSD 2080 Msida, Malta