Blog
About

37
views
1
recommends
+1 Recommend
0 collections
    1
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Porous translucent electrodes enhance current generation from photosynthetic biofilms

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Some photosynthetically active bacteria transfer electrons across their membranes, generating electrical photocurrents in biofilms. Devices harvesting solar energy by this mechanism are currently limited by the charge transfer to the electrode. Here, we report the enhancement of bioelectrochemical photocurrent harvesting using electrodes with porosities on the nanometre and micrometre length scale. For the cyanobacteria Nostoc punctiforme and Synechocystis sp. PCC6803 on structured indium-tin-oxide electrodes, an increase in current generation by two orders of magnitude is observed compared to a non-porous electrode. In addition, the photo response is substantially faster compared to non-porous anodes. Electrodes with large enough mesopores for the cells to inhabit show only a small advantage over purely nanoporous electrode morphologies, suggesting the prevalence of a redox shuttle mechanism in the electron transfer from the bacteria to the electrode over a direct conduction mechanism. Our results highlight the importance of electrode nanoporosity in the design of electrochemical bio-interfaces.

          Abstract

          Some microorganisms are able to generate electrons that can be externally harvested. Here the authors show an increase by two orders of magnitude in the photocurrent when two cyanobacterial strains are grown on nanopourous transparent conducting substrates, compared to traditional solid substrates.

          Related collections

          Most cited references 20

          • Record: found
          • Abstract: not found
          • Article: not found

          Determination of accurate extinction coefficients and simultaneous equations for assaying chlorophylls a and b extracted with four different solvents: verification of the concentration of chlorophyll standards by atomic absorption spectroscopy

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Electrically conductive bacterial nanowires produced by Shewanella oneidensis strain MR-1 and other microorganisms.

            Shewanella oneidensis MR-1 produced electrically conductive pilus-like appendages called bacterial nanowires in direct response to electron-acceptor limitation. Mutants deficient in genes for c-type decaheme cytochromes MtrC and OmcA, and those that lacked a functional Type II secretion pathway displayed nanowires that were poorly conductive. These mutants were also deficient in their ability to reduce hydrous ferric oxide and in their ability to generate current in a microbial fuel cell. Nanowires produced by the oxygenic phototrophic cyanobacterium Synechocystis PCC6803 and the thermophilic, fermentative bacterium Pelotomaculum thermopropionicum reveal that electrically conductive appendages are not exclusive to dissimilatory metal-reducing bacteria and may, in fact, represent a common bacterial strategy for efficient electron transfer and energy distribution.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Tunable metallic-like conductivity in microbial nanowire networks.

              Electronic nanostructures made from natural amino acids are attractive because of their relatively low cost, facile processing and absence of toxicity. However, most materials derived from natural amino acids are electronically insulating. Here, we report metallic-like conductivity in films of the bacterium Geobacter sulfurreducens and also in pilin nanofilaments (known as microbial nanowires) extracted from these bacteria. These materials have electronic conductivities of ∼5 mS cm(-1), which are comparable to those of synthetic metallic nanostructures. They can also conduct over distances on the centimetre scale, which is thousands of times the size of a bacterium. Moreover, the conductivity of the biofilm can be tuned by regulating gene expression, and also by varying the gate voltage in a transistor configuration. The conductivity of the nanofilaments has a temperature dependence similar to that of a disordered metal, and the conductivity could be increased by processing.
                Bookmark

                Author and article information

                Affiliations
                [1 ]ISNI 0000000121885934, GRID grid.5335.0, Cavendish Laboratory, Department of Physics, , University of Cambridge, ; Cambridge, CB3 0HE UK
                [2 ]ISNI 0000 0001 2364 4210, GRID grid.7450.6, III. Physikalisches Institut, , Georg-August-Universität, ; 37077 Göttingen, Germany
                [3 ]ISNI 0000000121885934, GRID grid.5335.0, Department of Biochemistry, , University of Cambridge, ; Hopkins Building, Cambridge, CB2 1QW UK
                [4 ]ISNI 0000 0004 0593 4718, GRID grid.478319.0, Adolphe Merkle Institute, ; Rue des Verdiers 4, 1700 Fribourg, Switzerland
                Contributors
                ch26@cam.ac.uk
                ORCID: http://orcid.org/0000-0001-5936-339X, ullrich.steiner@unifr.ch
                Journal
                Nat Commun
                Nat Commun
                Nature Communications
                Nature Publishing Group UK (London )
                2041-1723
                3 April 2018
                3 April 2018
                2018
                : 9
                3320
                10.1038/s41467-018-03320-x
                5880806
                © The Author(s) 2018

                Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

                Categories
                Article
                Custom metadata
                © The Author(s) 2018

                Uncategorized

                Comments

                Comment on this article