1. Inorganic Chemistry and Center for Nanointegration Duisburg–Essen (CeNIDE) University of Duisburg-Essen Universitätsstrasse 5–7 45117 Essen Germany
2. Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons Forschungszentrum Jülich GmbH 52425 Jülich Germany
3. Laboratory of Chemical Biology Department of Biomedical Engineering and Institute for Complex Molecular Systems (ICMS) Eindhoven University of Technology P.O. Box 513, 5600MB Eindhoven The Netherlands
4. Department of Structural and Medicinal Biochemistry Centre for Medical Biotechnology (ZMB), University of Duisburg-Essen 45117 Essen Germany