1. Department of BioengineeringImperial College LondonRoyal School of Mines SW7 2AZ London UK
2. University of FreiburgFreiburg Center for Interactive Materials and Bioinspired Technologies (FIT) 79110 Freiburg Germany
3. Laboratory for SensorsDepartment of Microsystems Engineering (IMTEK)University of Freiburg 79110 Freiburg Germany
4. REQUIMTE/LAQVInstituto Superior de Engenharia do Porto 4249‐015 Porto Portugal
5. Departamento de Química Física y AnalíticaUniversidad de Oviedo 33006 Oviedo Spain
6. Catalan Institute of Nanoscience and Nanotechnology (ICN2)CSIC and The Barcelona Institute of Science and Technology 08193 Barcelona Spain
7. ICREA 08010 Barcelona Spain
8. Korea Institute of Science and Technology in Europe 66123 Saarbrücken Germany
9. University of FreiburgFreiburg Materials Research Center (FMF) 79104 Freiburg Germany