1. ETH Zürich, Department of Chemistry and Applied Biosciences, Vladimir Prelog Weg 1-5, ETH Zürich, CH-8093 Zurich, Switzerland
2. Birck Nanotechnology Center, Purdue University, 1205 West State Street, West Lafayette, Indiana 47907, United States
3. Paul Scherrer Institut, CH-5232 Villigen, Switzerland