Liquid phase sensors based on chemically functionalized GaAs/AlGaAs heterostructures

S. M. Luber, K. Adlkofer, U. Rant, A. Ulman, A. Gölzhäuser, M. Grunze, D. Schuh, M. Tanaka, M. Tornow, G. Abstreiter

Research output: Contribution to journalConference articlepeer-review


We report on surface-near two-dimensional electron gases in GaAs/AlGaAs heterostructures for application in potential chemical or biochemical sensors in liquid environment. GaAs cap layers of the heterostructures were coated with self-assembled monolayers of 4′-substituted 4-mercaptobiphenyls (MBP), showing stable device performance in physiological (aqueous) buffers. Deposition of MBP with different 4′-substituents led to systematic changes in the lateral resistance, which can be correlated to the electrical potential drop across the established surface dipole layers. Furthermore, the lateral resistance showed a clear dependency on organic solvents with different polarities, suggesting its high sensitivity to the polarity of physisorbed molecules.

Original languageEnglish (US)
Pages (from-to)1111-1115
Number of pages5
JournalPhysica E: Low-Dimensional Systems and Nanostructures
Issue number2-4
StatePublished - Mar 2004
EventProceedings of the Eleventh International Conference on Modulation (MSS11) - Nara, Japan
Duration: Jul 14 2003Jul 18 2003


  • GaAs
  • Heterostructure
  • Self-assembled monolayer
  • Sensor
  • Two-dimensional electron gas

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics


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