1. Faculty of Physics, Babes-Bolyai University, M. Kogalniceanu Str. 1, 400084 Cluj-Napoca, Romania
2. Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, Treboniu Laurian 42, 400271 Cluj-Napoca, Romania
3. INCDO-INOE 2000, Research Institute for Analytical Instrumentation, Donath Street 67, 400293 Cluj-Napoca, Romania