1. Department of Electrical and Computer Engineering, University of Alberta, 9211-116 St., Edmonton, AB T6G 1H9, Canada
2. Nanotechnology Research Centre, National Research Council Canada, 11421 Saskatchewan Drive, Edmonton, AB T6G 2M9, Canada
3. Department of Materials Science and Engineering, Indian Institute of Technology Delhi, New Delhi 11016, India
4. MEMS, Microfluidics and Nanoelectronics (MMNE) Lab, Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Hyderabad 500078, India
5. Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada