1. Nanobioelectronics and Biosensors Group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
2. Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham Malaysia, 43500 Semenyih, Selangor Malaysia
3. Nanotechnology Research Group, Centre of Nanotechnology and Advanced Materials, University of Nottingham Malaysia, 43500 Semenyih, Selangor Malaysia
4. ICREA, Institució Catalana de Recerca i Estudis Avançats, Pg. Lluis Companys 23, 08010 Barcelona, Spain