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ORIGINAL RESEARCH article

Front. Phys.
Sec. Optics and Photonics
Volume 12 - 2024 | doi: 10.3389/fphy.2024.1481341
This article is part of the Research Topic Photonics in Nature: From Living Organisms to Bioinspiration View all 3 articles

The use of microbial rhodopsin proteins in differential photodetection

Provisionally accepted
Louisa Reissig Louisa Reissig 1,2,3*Kirstin Buchanan Kirstin Buchanan 4Thea Lindner Thea Lindner 1Marie Kurihara Marie Kurihara 5Po-Chuan Chan Po-Chuan Chan 1Falk Kibowski Falk Kibowski 1Keiichi Kojima Keiichi Kojima 5Simon Dalgleish Simon Dalgleish 2,3Kunio Awaga Kunio Awaga 2,3Yuki Sudo Yuki Sudo 5
  • 1 Fachbereich Physik, Freie Universität Berlin, Berlin, Germany
  • 2 Research Center for Materials Science, School of Science, Nagoya University, Nagoya, Aichi, Japan
  • 3 Department of Chemistry, School of Science, Nagoya University, Nagoya, Aichi, Japan
  • 4 School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK, Edinburgh, United Kingdom
  • 5 Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Okayama, Japan

The final, formatted version of the article will be published soon.

    Transferring information using light signals, and detecting these signals, is not only a cornerstone of modern technology, but has been essential for organisms since evolution provided them with proteins -the cell's custom-built tools -capable of light to energy conversion or photo-sensing. In this study, the use of diverse representatives of the photoactive protein family of microbial rhodopsins as the active material in differential photodetector devices has been investigated. By modifying the internal parameters of the detectors, such as rhodopsin kind, salinity and pH, as well as by tuning the external environment, such as temperature, we could increase the responsivity and speed of our devices by over 2 orders of magnitude, compared to a previously reported proof-of-concept device, to the µA/W and kHz range, respectively. The characteristic differential photodetector transient signal shape could be stably observed for temperatures up to 70°C and related to features in the protein's cyclic reaction upon light activation, with the changes in photocurrent shape and polarity concomitantly providing information about the protein used in the device. Furthermore, this study demonstrates that the use of proteins -the cell's molecular machines -instead of simple organic semiconductor materials can add secondary sensor functionalities to the device if the stimulus (here through temperature and pH) has sufficient effect on the photocurrent signal to allow calibration.

    Keywords: Photodetection, Microbial rhodopsin, MISM photodetector, Biotechnology, impedance spectroscopy

    Received: 15 Aug 2024; Accepted: 24 Oct 2024.

    Copyright: © 2024 Reissig, Buchanan, Lindner, Kurihara, Chan, Kibowski, Kojima, Dalgleish, Awaga and Sudo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Louisa Reissig, Fachbereich Physik, Freie Universität Berlin, Berlin, Germany

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