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Fabrication, Characterization, and Functionalization of Dual Carbon Electrodes as Probes for Scanning Electrochemical Microscopy (SECM)

McKelvey, Kim, Nadappuram, Binoy Paulose, Actis, Paolo, Takahashi, Yasufumi, Korchev, Yuri E., Matsue, Tomokazu, Robinson, Colin, Unwin, Patrick R. (2013) Fabrication, Characterization, and Functionalization of Dual Carbon Electrodes as Probes for Scanning Electrochemical Microscopy (SECM). Analytical Chemistry, 85 (15). pp. 7519-7526. ISSN 0003-2700. (doi:10.1021/ac401476z) (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/ac401476z

Abstract

Dual carbon electrodes (DCEs) are quickly, easily, and cheaply fabricated by depositing pyrolytic carbon into a quartz theta nanopipet. The size of DCEs can be controlled by adjusting the pulling parameters used to make the nanopipet. When operated in generation/collection (G/C) mode, the small separation between the electrodes leads to reasonable collection efficiencies of ca. 30%. A three-dimensional finite element method (FEM) simulation is developed to predict the current response of these electrodes as a means of estimating the probe geometry. Voltammetric measurements at individual electrodes combined with generation/collection measurements provide a reasonable guide to the electrode size. DCEs are employed in a scanning electrochemical microscopy (SECM) configuration, and their use for both approach curves and imaging is considered. G/C approach curve measurements are shown to be particularly sensitive to the nature of the substrate, with insulating surfaces leading to enhanced collection efficiencies, whereas conducting surfaces lead to a decrease of collection efficiency. As a proof-of-concept, DCEs are further used to locally generate an artificial electron acceptor and to follow the flux of this species and its reduced form during photosynthesis at isolated thylakoid membranes. In addition, 2-dimensional images of a single thylakoid membrane are reported and analyzed to demonstrate the high sensitivity of G/C measurements to localized surface processes. It is finally shown that individual nanometer-size electrodes can be functionalized through the selective deposition of platinum on one of the two electrodes in a DCE while leaving the other one unmodified. This provides an indication of the future versatility of this type of probe for nanoscale measurements and imaging.

Item Type: Article
DOI/Identification number: 10.1021/ac401476z
Subjects: Q Science
Q Science > QH Natural history
Q Science > QH Natural history > QH301 Biology
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Colin Robinson
Date Deposited: 03 Oct 2013 08:52 UTC
Last Modified: 29 May 2019 11:05 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/35360 (The current URI for this page, for reference purposes)
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