Oxygen-reducing enzyme cathodes produced from SLAC, a small laccase from Streptomyces coelicolor
Oxygen-reducing enzyme cathodes produced from SLAC, a small laccase from Streptomyces coelicolor
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DOI：
10.1016/j.bios.2007.11.004
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发表时间：
2008-03-14
影响因子：
12.6
通讯作者：
Barton, Scott Calabrese
中科院分区：
文献类型：
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作者：
Gallaway, Joshua;Wheeldon, Ian;Barton, Scott Calabrese
将细菌表达的漆酶，即coelicolor链霉菌的小漆酶（SLAC）结合到直接电子转移（ET）和介导电子转移（MET）设计的电极中，用于生物燃料电池。采用DET设计，用循环伏安法直接观察酶的氧化还原动力学，观察到氧化还原电位为0.43 V （SHE）。当被锇氧化还原时。聚合物中，氧还原阴极在pH值为7时保持最大活性，在900转/分和40摄氏度的条件下，在平面构型下产生1.5 mA/cm(2)，从而优于使用真菌Trametes versicolor漆酶（0.2mA/cm(2)）在相似条件下产生的酶电极。这种改善直接归因于SLAC和真菌漆酶动力学的差异。在酶的较高等电点以上的pH值下，观察到介导的SLAC电极的最大稳定性，阴离子酶分子可以与阳离子介质形成静电加合物。在上述条件下，增加表面积的多孔复合SLAC电极在0.3 V （SHE）下产生的电流密度为6.25 mA/cm(2)。(c) 2007 Elsevier B.V.版权所有
The bacterially-expressed laccase, small laccase (SLAC) of Streptomyces coelicolor, was incorporated into electrodes of both direct electron transfer (]:)ET) and mediated electron transfer (MET) designs for application in biofuel cells. Using the DET design, enzyme redox kinetics were directly observable using cyclic voltammetry, and a redox potential of 0.43 V (SHE) was observed. When mediated by an osmium redox. polymer, the oxygen-reducing cathode retained maximum activity at pH 7, producing 1.5 mA/cm(2) in a planar configuration at 900 rpm and 40 degrees C, thus outperforming enzyme electrodes produced using laccase from fungal Trametes versicolor (0.2mA/cm(2)) under similar conditions. This improvement is directly attributable to differences in the kinetics of SLAC and fungal laccases. Maximum stability of the mediated SLAC electrode was observed at pH above the enzyme's relatively high isoelectric point, where the anionic enzyme molecules could form an electrostatic adduct with the cationic mediator. Porous composite SLAC electrodes with increased surface area produced a current density of 6.25 mA/cm(2) at 0.3 V (SHE) under the above conditions. (c) 2007 Elsevier B.V. All rights reserved.