Mediatorless electrocatalytic oxygen reduction with catalase on mercury–gold amalgam microelectrodes

[Display omitted] •Direct bioelectrocatalysis with bovine liver catalase.•Oxygen reduction reaction overpotential is reduced by 200 mV.•Possibility of electrochemical detection of catalase without H2O2.•New insight into the mechanism of catalase action. Catalase is known for its ability to catalyze...

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Bibliographic Details
Published in:Electrochemistry communications 2021-12, Vol.133, p.107167, Article 107167
Main Authors: Roguska, Agata, Leśniewski, Adam, Opallo, Marcin, Nogala, Wojciech
Format: Article
Language:English
Subjects:
Cyclic voltammetry
Direct biocatalysis
Enzyme
Hemispherical microelectrode
Mercury–gold amalgam
ORR
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Summary:[Display omitted] •Direct bioelectrocatalysis with bovine liver catalase.•Oxygen reduction reaction overpotential is reduced by 200 mV.•Possibility of electrochemical detection of catalase without H2O2.•New insight into the mechanism of catalase action. Catalase is known for its ability to catalyze disproportionation of hydrogen peroxide into oxygen and water. This work reports the oxygen reduction reaction (ORR) catalyzed by catalase, with a decreased activation energy manifested by a positive shift (+0.2 V) in onset potential. Direct bioelectrocatalysis with bovine liver catalase on a mercury–gold amalgam microelectrode is demonstrated. The background oxygen reduction reaction on the amalgam surface is inhibited by the protein, while the hydrogen evolution reaction (HER) is facilitated. Catalase molecules whose prosthetic groups are not wired to the electrode retain their intrinsic activity towards disproportionation of H2O2 generated at the electrode. The Hg–Au amalgam electrode may also be used to detect dissolved catalase in the absence of its substrate (H2O2) in the solution.
ISSN:1388-2481
1873-1902
DOI:10.1016/j.elecom.2021.107167