Bioelectrochemical Study of Thermostable Pycnoporus sanguineus CS43 Laccase Bioelectrodes Based on Pyrolytic Carbon Nanofibers for Bioelectrocatalytic O2 Reduction

Abstract

In this study, the bioelectrocatalytic reduction of molecular oxygen by two highly thermostable laccase isoforms from a native strain of Pycnoporus sanguineus CS43 were evaluated and compared to commercially available laccase from Trametes versicolor (TvL). The laccase isoforms (LAC1 and LAC2) and TvL laccase were immobilized by orientation onto anthracene-modified multiwalled carbon nanotubes (AC-MWCNT), which were subsequently immobilized onto carbon nanofiber mat electrodes fabricated using a carbon MEMS (C-MEMS) process. The performances of the isoforms were evaluated at differing pHs, temperatures, and with various inhibitors under hydrodynamic and hydrostatic conditions. Both LAC1 and LAC2 had onset potentials of over +650 mV vs Ag/AgCl at pH 4.0, which are among the highest reported to date for any laccase bioelectrode. High current densities were also obtained, producing 825 ± 88 μA/cm² and 1220 ± 106 μA/cm² with LAC1 and LAC2, respectively. The bioelectrodes also demonstrated remarkable operation...

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DOI

10.1021/ACSCATAL.5B01600

Journal

ACS Catalysis

Year

2015