1. School of Chemical Engineering The University of New South Wales Sydney NSW 2052 Australia
2. Australian Centre for NanoMedicine The University of New South Wales Sydney NSW 2052 Australia
3. School of Chemistry The University of New South Wales Sydney NSW 2052 Australia
4. School of Materials Science and Engineering Central South University Changsha 410083 China
5. Electron Microscope Unit The University of New South Wales Sydney NSW 2052 Australia
6. Department of Nanoengineering University of California San Diego La Jolla CA 92093 USA
7. Graduate School of Biomedical Engineering The University of New South Wales Sydney NSW 2052 Australia