1. Institute of Condensed Matter and Nanoscience, Université catholique de Louvain, 1 Place Louis Pasteur, 1348 Louvain-la-Neuve, Belgium
2. Louvain Drug Research Institute, Université catholique de Louvain, Avenue Mounier 73, 1200 Woluwe-Saint-Lambert, Belgium
3. National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK
4. Present address: PerkinElmer Inc., 6-501 Rowntree Dairy Rd, Woodbridge, ON L4L 8H1, Canada
5. Centre for Proteomics (CFP), University of Antwerp, Groenenborgerlaan 171, B2020 Antwerp, Belgium
6. Flemish Institute for Technological Research (VITO), Boeretang 200, B-2400 Mol, Belgium
7. Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium