1. Department of Chemical Sciences (formerly Applied Chemistry), University of Johannesburg Doornfontein Campus, P.O. Box 17011, Doornfontein, Johannesburg, South Africa
2. Centre for Nanomaterials Science Research, University of Johannesburg Doornfontein Campus, Johannesburg, South Africa
3. Biochemistry & Toxicology Section, National Institute for Occupational Health, Johannesburg, South Africa
4. Haematology and Molecular Medicine, University of the Witwatersrand, Johannesburg, South Africa