1. Instituto de Ciencia de Materiales de Sevilla (CSIC-US), c/Américo Vespucio, 49, Seville 41092, Spain
2. Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
3. Nick Holonyak Jr Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
4. Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
5. Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
6. Center for Genomic Diagnostics, Woese Institute for Genomic Biology, Urbana, Illinois 61801, United States