A Self-Powered Ethanol Biosensor

作者：Ruff Adrian; Pinyou Piyanut; Nolten Melinda; Conzuelo Felipe; Schuhmann Wolfgang

来源：ChemElectroChem, 2017, 4(4): 890-897.

DOI：10.1002/celc.201600864

• self-powered sensor
• biofuel cell
• enzyme electrodes
• redox polymers
• ethanol

We describe the fabrication of a self-powered ethanol biosensor comprising a beta-NAD(+)-dependent alcohol dehydrogenase (ADH) bioanode and a bienzymatic alcohol oxidase (AOx) and horseradish peroxidase (HRP) biocathode. beta-NAD(+) is regenerated by means of a specifically designed phenothiazine dye (i.e. toluidine blue, TB) modified redox polymer in which TB was covalently anchored to a hexanoic acid tethered poly(4-vinylpyridine) backbone. The redox polymer acts as an immobilization matrix for ADH. Using a carefully chosen anchoring strategy through the formation of amide bonds, the potential of the TB-based mediator is shifted to more positive potentials, thus preventing undesired O-2 reduction. To counterbalance the rather high potential of the TB-modified polymer, and thus the bioanode, a high-potential AOx/HRP-based biocathode is suggested. HRP is immobilized in a direct-electron-transfer regime on screen-printed graphite electrodes functionalized with multi-walled carbon nanotubes. The nanostructured cathode ensures the wiring of the iron-oxo complex within oxidized HRP, and thus a high potential for the reduction of H2O2 of about +550mV versus Ag/AgCl/3M KCl. The proposed biofuel cell exhibits an open-circuit voltage (OCV) of approximately 660mV and was used as self-powered device for the determination of the ethanol content in liquor.

• 出版日期2017-4