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Licensed Unlicensed Requires Authentication Published by De Gruyter August 15, 2022

Terahertz subwavelength sensing with bio-functionalized germanium fano-resonators

  • Carlos Alvarado Chavarin , Elena Hardt , Oliver Skibitzki , Thomas Voss , Mohammed Eissa , Davide Spirito , Giovanni Capellini , Leonetta Baldassarre , Julia Flesch , Jacob Piehler , Changjiang You ORCID logo , Sönke Grüssing , Friedhard Römer and Bernd Witzigmann ORCID logo EMAIL logo
From the journal Frequenz


Localized Surface Plasmon Resonances (LSPR) based on highly doped semiconductors microstructures, such as antennas, can be engineered to exhibit resonant features at THz frequencies. In this work, we demonstrate plasmonic antennas with increased quality factor LSPRs from Fano coupling to dark modes. We also discuss the advances in the biofunctionalization of n-doped Ge antennas for specific protein immobilization and cell interfacing. Finally, albumin biolayers with a thickness of a few hundred nanometers are used to demonstrate the performance of the fano-coupled n-Ge antennas as sensors. A resonant change of over 10% in transmission, due to the presence of the biolayer, can be detected within a bandwidth of only 20 GHz.

Corresponding author: Bernd Witzigmann, Department of Electrical-Electronic-Communication Engineering, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen-Nürnberg, Germany, E-mail:

Award Identifier / Grant number: ESSENCE 272553338


The work presented has been funded in part by the German Research Foundation (DFG) within the project ESSENCE (Electromagnetic Sensors for the Life Sciences).

  1. Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: Funder Name: Deutsche Forschungsgemeinschaft, Funder Id: 10.13039/501100001659, Grant Number: ESSENCE Program 272553338.

  3. Conflict of interest statement: The authors declare no conflicts of interest regarding this article.


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Received: 2022-04-12
Accepted: 2022-08-01
Published Online: 2022-08-15
Published in Print: 2022-12-16

© 2022 Walter de Gruyter GmbH, Berlin/Boston

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