title: Sensing photosynthetic herbicides in an electrochemical flow cell.
abstract: Specific inhibitory reactions of herbicides with photosynthetic reaction centers bound to working electrodes were monitored in a conventional electrochemical cell and a newly designed microfluidic electrochemical flow cell. In both cases, the bacterial reaction centers were bound to a transparent conductive metal oxide, indium-tin-oxide, electrode through carbon nanotubes. In the conventional cell, photocurrent densities of up to a few μA/cm2could be measured routinely. The photocurrent could be blocked by the photosynthetic inhibitor terbutryn (I50= 0.38 ± 0.14 μM) and o-phenanthroline (I50= 63.9 ± 12.2 μM). The microfluidic flow cell device enabled us to reduce the sample volume and to simplify the electrode arrangement. The useful area of the electrodes remained the same (ca. 2 cm2), similar to the classical electrochemical cell; however, the size of the cell was reduced considerably. The microfluidic flow control enabled us monitoring in real time the binding/unbinding of the inhibitor and cofactor molecules at the secondary quinone site.
authors.affiliation: Department of Medical Physics and Informatics, University of Szeged, H-6720, Rerrich B. tér 1, Szeged, Hungary.
authors.forename: Tibor
authors.initials: T
authors.lastname: Szabó
authors.affiliation: Department of Medical Physics and Informatics, University of Szeged, H-6720, Rerrich B. tér 1, Szeged, Hungary.
authors.forename: Richárd
authors.initials: R
authors.lastname: Csekő
authors.affiliation: Department of Medical Physics and Informatics, University of Szeged, H-6720, Rerrich B. tér 1, Szeged, Hungary.
authors.forename: Kata
authors.initials: K
authors.lastname: Hajdu
authors.affiliation: Biological Research Centre, Institue of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Krisztina
authors.initials: K
authors.lastname: Nagy
authors.affiliation: Biological Research Centre, Institue of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Sipos
authors.affiliation: Biological Research Centre, Institue of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Galajda
authors.affiliation: Biological Research Centre, Institue of Plant Biology, Hungarian Academy of Sciences, Szeged, Hungary.|Biofotonika R&D Ltd., Szeged, Hungary.
authors.forename: Győző
authors.initials: G
authors.lastname: Garab
authors.affiliation: Department of Medical Physics and Informatics, University of Szeged, H-6720, Rerrich B. tér 1, Szeged, Hungary. lnagy@sol.cc.u-szeged.hu.
authors.forename: László
authors.identifier: http://orcid.org/0000-0003-4750-2086
authors.initials: L
authors.lastname: Nagy
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004563:Electrochemistry / Q000295:instrumentation*; D006540:Herbicides; D010788:Photosynthesis / Q000502:physiology*
chemical_list: D006540:Herbicides
keywords: Biocomposites; Bioelectronics; Herbicide biosensors; Photocurrent; Photosynthesis