1. Technical and Macromolecular Chemistry Paderborn University Warburger Str. 100 33098 Paderborn Germany
2. Biohybrid Materials Department of Bioproducts and Biosystems Aalto University P.O. Box 16100 Aalto 00076 Finland
3. Dipartimento di Fisica Università di Bari and Sezione INFN di Bari Bari 70126 Italy