1. Biomedical Nanosensors Fraunhofer Institute for Microelectronic Circuits and Systems Finkenstrasse 61 47057 Duisburg Germany
2. Department EBS University Duisburg-Essen Bismarckstrasse 81 47057 Duisburg Germany
3. Physical Chemistry Ruhr-University Bochum Universitätsstrasse 150 44801 Bochum Germany