1. School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
2. The University of Sydney Nano Institute (Sydney Nano), The University of Sydney, Sydney, New South Wales 2006, Australia
3. Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, New South Wales 2006, Australia
4. Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom