1. Institute of Physiological Chemistry, University of Duisburg-Essen, University Hospital Essen, Essen, Germany;
2. Department of Physical Chemistry, University of Duisburg-Essen, Essen, Germany;
3. Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Duisburg, Germany;
4. Institute of Physiology, University of Duisburg-Essen, University Hospital Essen, Essen, Germany