title: Design of an Os Complex-Modified Hydrogel with Optimized Redox Potential for Biosensors and Biofuel Cells.
abstract: Multistep synthesis and electrochemical characterization of an Os complex-modified redox hydrogel exhibiting a redox potential ≈+30 mV (vs. Ag/AgCl 3 M KCl) is demonstrated. The careful selection of bipyridine-based ligands bearing N,N-dimethylamino moieties and an amino-linker for the covalent attachment to the polymer backbone ensures the formation of a stable redox polymer with an envisaged redox potential close to 0 V. Most importantly, the formation of an octahedral N6-coordination sphere around the Os central atoms provides improved stability concomitantly with the low formal potential, a low reorganization energy during the Os(3+/2+) redox conversion and a negligible impact on oxygen reduction. By wiring a variety of enzymes such as pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase, flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase and the FAD-dependent dehydrogenase domain of cellobiose dehydrogenase, low-potential glucose biosensors could be obtained with negligible co-oxidation of common interfering compounds such as uric acid or ascorbic acid. In combination with a bilirubin oxidase-based biocathode, enzymatic biofuel cells with open-circuit voltages of up to 0.54 V were obtained.
authors.affiliation: Analytical Chemistry, Center for Electrochemical Sciences (CES), Ruhr-Universität-Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
authors.forename: Piyanut
authors.identifier: http://orcid.org/0000-0001-7978-1898
authors.initials: P
authors.lastname: Pinyou
authors.affiliation: Analytical Chemistry, Center for Electrochemical Sciences (CES), Ruhr-Universität-Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
authors.forename: Adrian
authors.identifier: http://orcid.org/0000-0001-5659-8556
authors.initials: A
authors.lastname: Ruff
authors.affiliation: Analytical Chemistry, Center for Electrochemical Sciences (CES), Ruhr-Universität-Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
authors.forename: Sascha
authors.identifier: http://orcid.org/0000-0002-6613-2247
authors.initials: S
authors.lastname: Pöller
authors.affiliation: Department of Food Sciences and Technology, Vienna Institute of Biotechnology, BOKU - University of Natural Resources and Life Sciences, Muthgasse 11/1/56, 1190, Vienna, Austria.
authors.forename: Su
authors.initials: S
authors.lastname: Ma
authors.affiliation: Department of Food Sciences and Technology, Vienna Institute of Biotechnology, BOKU - University of Natural Resources and Life Sciences, Muthgasse 11/1/56, 1190, Vienna, Austria.
authors.forename: Roland
authors.identifier: http://orcid.org/0000-0002-5058-5874
authors.initials: R
authors.lastname: Ludwig
authors.affiliation: Analytical Chemistry, Center for Electrochemical Sciences (CES), Ruhr-Universität-Bochum, Universitätsstrasse 150, 44780, Bochum, Germany. wolfgang.schuhmann@rub.de.
authors.forename: Wolfgang
authors.identifier: http://orcid.org/0000-0003-2916-5223
authors.initials: W
authors.lastname: Schuhmann
mesh_terms: D001674:Bioelectric Energy Sources; D015374:Biosensing Techniques; D002237:Carbohydrate Dehydrogenases / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry*; D004566:Electrodes; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry*; D005948:Glucose Dehydrogenases / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D009992:Osmium / Q000737:chemistry*; D010084:Oxidation-Reduction; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D005182:Flavin-Adenine Dinucleotide; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D009992:Osmium; D002237:Carbohydrate Dehydrogenases; D005948:Glucose Dehydrogenases; C033955:glucose dehydrogenase (pyrroloquinoline-quinone); C019859:cellobiose-quinone oxidoreductase; D044925:Oxidoreductases Acting on CH-CH Group Donors; C042401:bilirubin oxidase
keywords: biosensors; hydrogel; osmium; polymers; redox chemistry