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Peter Grünberg Institute / Institute of Complex Systems

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Before a novel biolectronic devices as for instance a bioelectrochemical rectifier can be realized on micro or nanometer scale, it is recommendable to first evaluate immobilization strategies and to characterize the electrochemical properties of the identified (redox active) biomolecules at macroscopic electrodes. A variety of immobilization strategies exist enabling the wiring of biomolecules to conducting substrates. We primarily focus on the development and investigation of new immobilization strategies to optimize the electrical communication between electrode and biomolecule. Besides covalent binding strategies we engineer recombinant proteins and incorporate specific binding tags (e.g. his-tag) into the amino acid sequence to enable a high affinity immobilization. The immobilization process and the charge transfer kinetics of the biomolecules are characterized by electrochemical, spectroscopic, and scanning probe techniques.

The 2D macroelectrodes are furthermore used to evaluate the functionality of novel bioelectronic devices where redoxactive biomolecules are utilized as building blocks. Here, we are using on the one hand biological recognition for sensing applications and on the other hand bioelectronic properties like current rectification to realize logical operations. The findings gained from investigations on 2D macroelectrodes can later be used for the assembling of micro- and nanosized bioelectronic junctions.

Tailored Immobilization

Tailored Immobilization

We develop new strategies for the directed bivalent immobilization of redox proteins on or between gold electrodes by engineering modification with cys- or his-tag to their N- or C-terminus. In combination with electrostatic protein binding, these tags enable a bifunctional immobilization between two electrodes or alternatively one electrode and interacting enzymes.Such immobilized proteins are of interest for the development of novel bioelectronic / biosensing devices where electroactive proteins are immobilized between two crossing electrodes or bridging a nano gap.

Electrochemical logic gates

Electrochemical logic gates

Concepts have been realized to perform logical operations based on charge transfer processes between solved redox probes and metal electrodes mediated by surface bound redox molecules/enzymes. The resulting electrochemical current rectifier (ECR) can be utilized as trandsuser unit for the detection of biochemical signals, as recently demonstrated by realizing cytosensor for cancer cell detection. We also showed that electrochemical current rectifiers  can be integrated into molecular level logic gates with a high switch ratio between electrical output signals “1” and “0”. Our goal is to combine logic and sensing operations for advanced sensor performance.

Additional Information


Dr. Dirk Mayer

Tel.:  +49-2461-61-4023


H. Li, D. Li, J. Liu, Y. Qin, J. Ren, S. Xu,Y. Liu, D. Mayer, E. Wang, Electrochemical current rectifier as a highly sensitive and selective cytosensor for cancer cell detection, Chem. Commun.,  48, (2012) 2594, DOI: 10.1039/c2cc17591f


Y. Liu, A. Offenhäusser, D. Mayer, Electrochemical current rectification at bio-functionalized electrodes, Bioelectrochemistry, 77, (2010) 89, doi:10.1016/j.bioelechem.2009.06.015


Y. Liu, A. Offenhäusser, D. Mayer, An Electrochemically Transduced XOR Logic Gate at the Molecular Level, Angew. Chem. Int. Ed., 49, (2010) doi:10.1002/anie.200906333


F. Schröper, A. Baumann, A. Offenhäusser, D. Mayer, Direct electrochemistry of novel affinity-tag immobilized recombinant horse heart cytochrome c, Biosensors and Bioelectronics 34, (2012) 171, doi:10.1016/j.bios.2012.01.039


F. Schröper, A. Baumann, A. Offenhäusser, D. Mayer, Bidirectional immobilization of affinity-tagged cytochrome c on electrode surfaces, Chem. Commun., 46, (2010) 5295, doi:10.1039/c0cc00850h


F. Schröper, D. Brüggemann, Y. Mourzina, B. Wolfrum, A. Offenhäusser, D. Mayer, Analyzing the electroactive surface of gold nanopillars by electrochemical methods for electrode miniaturization, Electrochimica Acta, 53, (2008) 6265, doi:10.1016/j.electacta.2008.03.068


D. Mayer, K. Ataka, J. Heberle, A. Offenhäusser, Scanning Probe Microscopic Studies of the Oriented Attachment and Membrane Reconstitution of Cytochrome c Oxidase to a Gold Electrode, Langmuir,21, (2005) 8580, doi:10.1021/la051195x