1 Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, Brussels, B-1050, Belgium.
2 University of Amsterdam, van't Hoff Institute for Molecular Sciences (HIMS), Science Park 904, Amsterdam, 1098XH, Netherlands. Electronic address: p.j.schoenmakers@uva.nl.
3 VU University Amsterdam, Division of BioMolecular Analysis, de Boelelaan 1085, Amsterdam, 1081HV, Netherlands.