Influence of mediator redox potential on fuel sensitivity of mediated laccase oxygen reduction electrodes

Deboleena Chakraborty, Scott Calabrese Barton

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    • 6 Citations

    Abstract

    The impact of methanol on oxygen reduction activity is studied using a mediated biocathode catalyzed by laccase from Trametes versicolor. The sensitivity of oxygen reduction current density to the presence of methanol at such electrodes depends strongly on mediator redox potential. This study demonstrates that the selectivity of laccase cathodes toward oxygen reduction can allow methanol feed concentration up to 5 M in direct methanol fuel cells. Within the 0-5 M concentration range, methanol primarily affects enzyme kinetics and not the electron transport via the mediator. For methanol concentrations of 0-2.5 M, laccase activity toward oxygen was largely maintained; approximately 30 loss of activity occurred in the 2.5-5 M range, and irreversible loss of enzyme activity was observed beyond 7.5 M. The presence of methanol primarily decreases the turnover number of the enzyme rather than altering substrate binding, suggesting a noncompetitive inhibition mechanism. It is proposed that this reduction occurs due to changes in the electron transfer environment near the T1 binding pocket due to the presence of methanol.

    Original languageEnglish (US)
    JournalJournal of the Electrochemical Society
    Volume158
    Issue number4
    DOIs
    StatePublished - 2011

    Profile

    methyl alcohol
    Methanol
    Oxygen
    oxygen
    Electrodes
    Methacholine Compounds
    Autoradiography
    Oxidation-Reduction
    enzymes
    electrodes
    sensitivity
    Enzyme kinetics
    Direct methanol fuel cells (DMFC)
    Enzyme activity
    Cathodes
    Current density
    Enzymes
    Electrons
    Substrates
    Suckling Animals

    ASJC Scopus subject areas

    • Electrochemistry
    • Electronic, Optical and Magnetic Materials
    • Materials Chemistry
    • Surfaces, Coatings and Films
    • Renewable Energy, Sustainability and the Environment
    • Condensed Matter Physics

    Cite this

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    title = "Influence of mediator redox potential on fuel sensitivity of mediated laccase oxygen reduction electrodes",
    abstract = "The impact of methanol on oxygen reduction activity is studied using a mediated biocathode catalyzed by laccase from Trametes versicolor. The sensitivity of oxygen reduction current density to the presence of methanol at such electrodes depends strongly on mediator redox potential. This study demonstrates that the selectivity of laccase cathodes toward oxygen reduction can allow methanol feed concentration up to 5 M in direct methanol fuel cells. Within the 0-5 M concentration range, methanol primarily affects enzyme kinetics and not the electron transport via the mediator. For methanol concentrations of 0-2.5 M, laccase activity toward oxygen was largely maintained; approximately 30 loss of activity occurred in the 2.5-5 M range, and irreversible loss of enzyme activity was observed beyond 7.5 M. The presence of methanol primarily decreases the turnover number of the enzyme rather than altering substrate binding, suggesting a noncompetitive inhibition mechanism. It is proposed that this reduction occurs due to changes in the electron transfer environment near the T1 binding pocket due to the presence of methanol.",
    author = "Deboleena Chakraborty and Barton, {Scott Calabrese}",
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    volume = "158",
    journal = "Journal of the Electrochemical Society",
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    publisher = "Electrochemical Society, Inc.",
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    TY - JOUR

    T1 - Influence of mediator redox potential on fuel sensitivity of mediated laccase oxygen reduction electrodes

    AU - Chakraborty,Deboleena

    AU - Barton,Scott Calabrese

    PY - 2011

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    N2 - The impact of methanol on oxygen reduction activity is studied using a mediated biocathode catalyzed by laccase from Trametes versicolor. The sensitivity of oxygen reduction current density to the presence of methanol at such electrodes depends strongly on mediator redox potential. This study demonstrates that the selectivity of laccase cathodes toward oxygen reduction can allow methanol feed concentration up to 5 M in direct methanol fuel cells. Within the 0-5 M concentration range, methanol primarily affects enzyme kinetics and not the electron transport via the mediator. For methanol concentrations of 0-2.5 M, laccase activity toward oxygen was largely maintained; approximately 30 loss of activity occurred in the 2.5-5 M range, and irreversible loss of enzyme activity was observed beyond 7.5 M. The presence of methanol primarily decreases the turnover number of the enzyme rather than altering substrate binding, suggesting a noncompetitive inhibition mechanism. It is proposed that this reduction occurs due to changes in the electron transfer environment near the T1 binding pocket due to the presence of methanol.

    AB - The impact of methanol on oxygen reduction activity is studied using a mediated biocathode catalyzed by laccase from Trametes versicolor. The sensitivity of oxygen reduction current density to the presence of methanol at such electrodes depends strongly on mediator redox potential. This study demonstrates that the selectivity of laccase cathodes toward oxygen reduction can allow methanol feed concentration up to 5 M in direct methanol fuel cells. Within the 0-5 M concentration range, methanol primarily affects enzyme kinetics and not the electron transport via the mediator. For methanol concentrations of 0-2.5 M, laccase activity toward oxygen was largely maintained; approximately 30 loss of activity occurred in the 2.5-5 M range, and irreversible loss of enzyme activity was observed beyond 7.5 M. The presence of methanol primarily decreases the turnover number of the enzyme rather than altering substrate binding, suggesting a noncompetitive inhibition mechanism. It is proposed that this reduction occurs due to changes in the electron transfer environment near the T1 binding pocket due to the presence of methanol.

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