1. Center for Education and Research on Macromolecules (CERM), University of Liège, Sart-Tilman, B6, B-4000 Liège, Belgium, Laboratory of Analytical Chemistry and Electrochemistry, University of Liège, Sart-Tilman, B6, B-4000 Liège, Belgium, Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, and Service de Chimie Inorganique et Analytique LASSIE, University of Mons-Hainaut, Av. Nicolas Copernic, B-7000 Mons, Belgium