1. Nanosciences African Network, iThemba LABS, Materials Research Department, National Research Foundation, PO Box 722, Somerset West, South Africa
2. Chemistry and Polymer Science Department, Stellenbosch University, Matieland, Stellenbosch, 7602, South Africa
3. Synthetic Biology-Biosciences, CSIR, Meiring Naude, Pretoria 0001, South Africa
4. Dept. of Physics, University of Kwazulu-Natal, Private Bag X01, Scottsville 3209, Scottsville, South Africa
5. Angstrom laboratory, Uppsala University, Uppsala, Sweden
6. Institute of Plant Biology, Biological Research Centre, PO Box 521, Szeged H-6701, Hungary
7. University of Angers, UFR Sciences, Institute of Sciences and Molecular Technologies of Angers, Moltech Anjou - UMR CNRS 6200, Molecular Interaction Nonlinear optics and Structuring MINOS, 2 Bd Lavois, 49000 Angers, France