Hydrogen peroxide produced by glucose oxidase affects the performance of laccase cathodes in glucose/oxygen fuel cells: FAD-dependent glucose dehydrogenase as a replacement
Hydrogen peroxide produced by glucose oxidase affects the performance of laccase cathodes in glucose/oxygen fuel cells: FAD-dependent glucose dehydrogenase as a replacement
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DOI：
10.1039/c3cp53351d
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发表时间：
2013-01-01
影响因子：
3.3
通讯作者：
Slade, Robert C. T.
中科院分区：
文献类型：
--
作者：
Milton, Ross D.;Giroud, Fabien;Slade, Robert C. T.
研究了葡萄糖氧化酶 (GOx) 产生的过氧化氢及其对漆酶性能的负面影响。同时，FAD 依赖性葡萄糖脱氢酶 (FAD-GDH)（一种 O2 不敏感酶）已作为替代品进行了评估。实验的重点是确定电解质中 GOx 的天然电子受体 O-2（消耗）和过氧化氢（产生）之间的副反应的影响。首先，研究了 GOx 和 FAD-GDH 在底物存在下的耗氧量。两种酶均获得了相对较高的电催化电流。仅使用固定化 GOx 观察到 O-2 消耗，而 FAD-GDH 的 O-2 浓度保持稳定。通过浸入单个隔室中的氧化电极和还原电极研究了溶解氧消耗对漆酶电极性能的影响。在存在葡萄糖的情况下，当漆酶电极仅与基于 GOx 的电极组合时，记录到阴极电流急剧下降。此外，阴极性能的主要损失似乎是由于本体溶液中 H2O2 浓度的增加引起漆酶抑制。 24小时稳定性实验表明，使用O-2不敏感的FAD-GDH来避免GOx原位产生过氧化物是有效的。 FAD-GDH/漆酶生物燃料电池的开路电位为0.66 +/- 0.03 V，功率密度为122.2 +/- 5.8 mW cm(-2)。
Hydrogen peroxide production by glucose oxidase (GOx) and its negative effect on laccase performance have been studied. Simultaneously, FAD-dependent glucose dehydrogenase (FAD-GDH), an O2-insensitive enzyme, has been evaluated as a substitute. Experiments focused on determining the effect of the side reaction of GOx between its natural electron acceptor O-2 (consumed) and hydrogen peroxide (produced) in the electrolyte. Firstly, oxygen consumption was investigated by both GOx and FAD-GDH in the presence of substrate. Relatively high electrocatalytic currents were obtained with both enzymes. O-2 consumption was observed with immobilized GOx only, whilst O-2 concentration remained stable for the FAD-GDH. Dissolved oxygen depletion effects on laccase electrode performances were investigated with both an oxidizing and a reducing electrode immersed in a single compartment. In the presence of glucose, dramatic decreases in cathodic currents were recorded when laccase electrodes were combined with a GOx-based electrode only. Furthermore, it appeared that the major loss of performance of the cathode was due to the increase of H2O2 concentration in the bulk solution induced laccase inhibition. 24 h stability experiments suggest that the use of O-2-insensitive FAD-GDH as to obviate in situ peroxide production by GOx is effective. Open-circuit potentials of 0.66 +/- 0.03 V and power densities of 122.2 +/- 5.8 mW cm(-2) were observed for FAD-GDH/ laccase biofuel cells.