1. Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, SK-84511 Bratislava, Slovakia
2. Center for Advanced Materials Application, Slovak Academy of Sciences, Dúbravská Cesta 9, SK-84511 Bratislava, Slovakia
3. Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská Cesta 21, SK-84551 Bratislava, Slovakia
4. Istituto Chimica Biomolecolare-Consiglio Nazionale Delle Ricerche, Via Paolo Gaifami 18, 95126 Catania, Italy