Skip to main content

Quantitative Local Photosynthetic Flux Measurements at Isolated Chloroplasts and Thylakoid Membranes Using Scanning Electrochemical Microscopy (SECM)

McKelvey, Kim, Martin, Sophie, Robinson, Colin, Unwin, Patrick R. (2013) Quantitative Local Photosynthetic Flux Measurements at Isolated Chloroplasts and Thylakoid Membranes Using Scanning Electrochemical Microscopy (SECM). Journal of Physical Chemistry B, 117 (26). pp. 7878-7888. ISSN 1520-6106. (doi:10.1021/jp403048f) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1021/jp403048f

Abstract

Scanning electrochemical microscopy (SECM) offers a fast and quantitative method to measure local fluxes within photosynthesis. In particular, we have measured the flux of oxygen and ferrocyanide (Fe(CN)64–), from the artificial electron acceptor ferricyanide (Fe(CN)63–), using a stationary ultramicroelectrode at chloroplasts and thylakoid membranes (sourced from chloroplasts). Oxygen generation at films of chloroplasts and thylakoid membranes was detected directly during photosynthesis, but in the case of thylakoid membranes, this switched to sustained oxygen consumption at longer illumination times. An initial oxygen concentration spike was detected over both chloroplast and thylakoid membrane films, and the kinetics of the oxygen generation were extracted by fitting the experimental data to a finite element method (FEM) simulation. In contrast to previous work, the oxygen generation spike was attributed to the limited size of the plastoquinone pool, a key component in the linear electron transport pathway and a contributing factor in photoinhibition. Finally, the mobile nature of the SECM probe, and its high spatial resolution, also allowed us to detect ferrocyanide produced from a single thylakoid membrane. These results further demonstrate the power of SECM for localized flux measurements in biological processes, in this case photosynthesis, and that the high time resolution, combined with FEM simulations, allows the elucidation of quantitative kinetic information.

Item Type: Article
DOI/Identification number: 10.1021/jp403048f
Subjects: Q Science
Q Science > Q Science (General)
Q Science > QD Chemistry
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Colin Robinson
Date Deposited: 10 Jul 2013 09:14 UTC
Last Modified: 23 Jan 2020 04:07 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/34569 (The current URI for this page, for reference purposes)
Robinson, Colin: https://orcid.org/0000-0002-1739-032X
  • Depositors only (login required):