1. UNESCO-UNISA Africa Chair in Nanosciences & Nanotechnology Laboratories (U2AC2N), College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, Pretoria 0003, South Africa
2. Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, Somerset West 7129, South Africa
3. School of Pharmacy, University of the Western Cape, Bellville 7535, South Africa