Graphene Biosensors

Biosensing and bioelectronic applications have enormously profited from employing field-effect transistors as transducing devices, mainly due to their intrinsic amplification capability and the high integration offered by semiconductor technology. The sensitivity of so-called solution-gated FETs (SGFETs) largely depends on the charge carrier mobility and the distance between the conductive channel and the surface. On both counts, graphene – a monolayer of sp²-bonded carbon - appears as an ideal candidate for the development of highly sensitive SGFETs.
Furthermore, the high chemical and mechanical stability of graphene suggest its use in aqueous environments as e.g. biological systems. Due to the exceptional band structure of graphene, both electrons and holes can be observed and tuned by electrolytic gating.
As micrometer-sized transistors are beneficial for many biophysical experiments, large-scale graphene films are grown by chemical vapor deposition (CVD) on copper foil. The graphene is transferred to various substrates and microscopic graphene SGFET arrays are fabricated. The devices are characterized in aqueous environments using standard transistor characterization as well as advanced techniques such as in-liquid Hall-effect and low-frequency noise measurements.

People on the project:

Lucas Hess, Max Seifert, Eric Parzinger, Benno Blaschke
This work is done in the frame of a joint DFG project with the group of Dr. Ian Sharp (WSI, TUM)

Selected publications:

• Graphene Solution-Gated Field-Effect Transistor Array for Sensing Applications
  M. Dankerl, M.V. Hauf, A. Lippert, L.H. Hess, S. Birner, I.D. Sharp, A. Mahmood, P. Mallet, J.-Y. Veuillen, M. Stutzmann, and J.A. Garrido
  Advanced Functional Materials 20, 3117–3124 (2010)
  Online Reference
• High-transconductance graphene solution-gated field effect transistors
  L. H. Hess, M. V. Hauf, M. Seifert, F. Speck, T. Seyller, M. Stutzmann, I. D. Sharp, and J. A. Garrido
  Applied Physics Letters 99, 033503 (2011)
  Online Reference
• Graphene Transistor Arrays for Recording Action Potentials from Electrogenic Cells
  L. H. Hess, M. Jansen, V. Maybeck, M. V. Hauf, M. Seifert, M. Stutzmann, I. D. Sharp, A. Offenhäusser, and J. A. Garrido
  Advanced Materials 23, 5045-5049 (2011)
  Online Reference
  Please see also the TUM press release on this paper:English version; Deutsche Version
  and the Outlook article in Nature 483, S37 (2012)

Cooperations:

Tomás Palacios, Massachusetts Institute of Technology, Cambridge, MA, USA

Jean-Yves Veuillen, Institut Néel, CNRS-Université Joseph Fourier, Grenoble, France

Kian Ping Loh, National University of Singapore

Heiko B. Weber and Thomas Seyller, Universität Erlangen

Funding:

DFG: priority program Graphene SPP 1459 – project: GA 1432/2-1,
Nanosystems Initiative Munich (NIM),
MIT Center for International Studies Global Seed Fund