Functional peptides for capacitative detection of Ca2+ ions

Authors

  • Martina Hitzbleck,

    1. Peter-Grünberg Institute, PGI-8, Forschungszentrum Jülich GmbH, and JARA Fundamentals of Future Information Technology, 52425 Jülich, Germany
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  • Xuan Thang Vu,

    1. Department of Informatics and Microsystem Technology, University of Applied Sciences Kaiserslautern, Campus Zweibrücken, 66482 Zweibrücken, Germany
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  • Sven Ingebrandt,

    1. Department of Informatics and Microsystem Technology, University of Applied Sciences Kaiserslautern, Campus Zweibrücken, 66482 Zweibrücken, Germany
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  • Andreas Offenhäusser,

    1. Peter-Grünberg Institute, PGI-8, Forschungszentrum Jülich GmbH, and JARA Fundamentals of Future Information Technology, 52425 Jülich, Germany
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  • Dirk Mayer

    Corresponding author
    • Peter-Grünberg Institute, PGI-8, Forschungszentrum Jülich GmbH, and JARA Fundamentals of Future Information Technology, 52425 Jülich, Germany
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Abstract

Molecular recognition is the key feature of bioinspired sensor applications. A profound understanding of recognitive binding events is crucial for the design of highly specific and effective binding molecules. In this paper a series of simple to complex oligopeptides, derived from the Ca2+ chelator ethylenediaminetetraacetic acid (EDTA) and the Ca2+ binding protein calmodulin, were investigated. It was shown, that specifically designed oligopeptides can fulfil protein-like recognition functions but are much easier to immobilize and enable high functional integration. Impedance spectroscopy (IS) could be used to detect binding of Ca2+ to different peptides because the double layer capacitance is highly sensitive to changes in the morphology and dielectric properties of adsorbate layers. Finally, the designed functional oligopeptides were implemented in silicon nanowire field effect transistors (SiNW FETs) as a proof of concept for future problem-optimized molecules in sensor devices. pssa201200886-gra-0001

The graph shows frequency-normalized admittance plots and corresponding schemes of a peptide monolayers layer before and after binding of Ca2+ ions.

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