Biomolecular control over local gating in bilayer graphene induced by ferritin
Senthil Kumar Karuppannan,
Jens Martin,
Wentao Xu,
Rupali Reddy Pasula,
Sierin Lim,
Christian A. Nijhuis
Affiliations
Senthil Kumar Karuppannan
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
Jens Martin
Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore; Department of Physics, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore; Corresponding author
Wentao Xu
Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
Rupali Reddy Pasula
School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore
Sierin Lim
School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore
Christian A. Nijhuis
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore; Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore; Hybrid Materials for Opto-Electronics Group, Department of Molecules and Materials, MESA+ Institute for Nanotechnology and Center for Brain-Inspired Nano Systems, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, the Netherlands; Corresponding author
Summary: Electrical field-induced charge modulation in graphene-based devices at the nanoscale with ultrahigh density carrier accumulation is important for various practical applications. In bilayer graphene (BLG), inversion symmetry can simply be broken by an external electric field. However, control over charge carrier density at the nanometer scale is a challenging task. We demonstrate local gating of BLG in the nanometer range by adsorption of AfFtnAA (which is a bioengineered ferritin, an iron-storing globular protein with ∅ = 12 nm). Low-temperature electrical transport measurements with field-effect transistors with these AfFtnAA/BLG surfaces show hysteresis with two Dirac peaks. One peak at a gate voltage VBG = 35 V is associated with pristine BLG, while the second peak at VBG = 5 V results from local doping by ferritin. This charge trapping at the biomolecular length scale offers a straightforward and non-destructive method to alter the local electronic structure of BLG.
