1. Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3000, Australia
2. Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping SE-58183, Sweden
3. ARC Centre of Excellence for Nanoscale BioPhotonics, School of Science, RMIT University, Melbourne, VIC 3001, Australia
4. RMIT Microscopy & Microanalysis Facility, STEM College, RMIT University, Melbourne, VIC 3000, Australia