1. Sri Lanka Institute of Nanotechnology (SLINTEC), Mahenwatte, Pitipana, Homagama 10200, Sri Lanka
2. Department of Chemistry, The Open University of Sri Lanka, Nawala 10250, Sri Lanka
3. Department of Engineering, University of Cambridge, Cambridge CB3 0HE, UK
4. Department of Chemistry, University of Colombo, Colombo 03 00300, Sri Lanka