Pinyou Piyanut, Ruff Adrian, Pöller Sascha, Ma Su, Ludwig Roland, Schuhmann Wolfgang
Analytical Chemistry, Center for Electrochemical Sciences (CES), Ruhr-Universität-Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
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.
Chemistry. 2016 Apr 4;22(15):5319-26. doi: 10.1002/chem.201504591. Epub 2016 Mar 1.
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.
展示了一种氧化还原电位约为 +30 mV（相对于 Ag/AgCl 3 M KCl）的锇配合物修饰的氧化还原水凝胶的多步合成和电化学表征。精心选择带有 N,N-二甲基氨基部分的联吡啶基配体和用于与聚合物主链共价连接的氨基连接体，确保形成具有接近 0 V 的预期氧化还原电位的稳定氧化还原聚合物。最重要的是，在锇中心原子周围形成八面体 N6 配位球，在提供低形式电位的同时提高了稳定性，在 Os(3+/2+) 氧化还原转化过程中具有低重组能，并且对氧还原的影响可忽略不计。通过连接多种酶，如吡咯并喹啉醌（PQQ）依赖性葡萄糖脱氢酶、黄素腺嘌呤二核苷酸（FAD）依赖性葡萄糖脱氢酶和纤维二糖脱氢酶的 FAD 依赖性脱氢酶结构域，可以获得低电位葡萄糖生物传感器，对尿酸或抗坏血酸等常见干扰化合物的共氧化可忽略不计。与基于胆红素氧化酶的生物阴极相结合，获得了开路电压高达 0.54 V 的酶促生物燃料电池。
