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Immobilization of Redox Enzymes on Nanoporous Gold Electrodes: Applications in Biofuel Cells
Author(s) -
Siepenkoetter Till,
SalajKosla Urszula,
Xiao Xinxin,
Conghaile Peter Ó,
Pita Marcos,
Ludwig Roland,
Magner Edmond
Publication year - 2017
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.201600455
Subject(s) - bilirubin oxidase , nanoporous , glucose oxidase , electrode , redox , immobilized enzyme , materials science , anode , chemistry , inorganic chemistry , biosensor , chemical engineering , nanotechnology , organic chemistry , enzyme , engineering
Nanoporous gold (NPG) electrodes were prepared by dealloying sputtered gold:silver alloys. Electrodes of different thicknesses and pore sizes areas were prepared by varying the temperature and duration of the dealloying procedure; these were then used as supports for FAD‐dependent glucose dehydrogenase (GDH) ( Glomorella cingulata ) and bilirubin oxidase (BOx) ( Myrothecium verrucaria ). Glucose dehydrogenase was immobilized by drop‐casting a solution of the enzyme with an osmium redox polymer together with a crosslinked polymer, whereas bilirubin oxidase was attached covalently through carbodiimide coupling to a diazonium‐modified NPG electrode. The stability of the bilirubin‐oxidase‐modified NPG electrode was significantly improved in comparison with that of a planar gold electrode. Enzyme fuel cells were also prepared; the optimal response was obtained with a BOx‐modified NPG cathode (500 nm thickness) and a GDH‐modified anode (300 nm), which generated power densities of 17.5 and 7.0 μW cm −2 in phosphate‐buffered saline and artificial serum, respectively.