Department of Bioproducts and Biosystems Engineering, Biotechnology Institute, University of Minnesota, St. Paul, 55108, USA.
Biotechnol Bioeng. 2009 Dec 15;104(6):1068-74. doi: 10.1002/bit.22496.
Carbon nanotubes (CNTs) have been used for various bioelectrochemical applications, presumably for substantial improvement in performance. However, often only moderate results observed, with many governing factors have been considered and suggested yet without much systematic evaluation and verification. In this study, CNT-supported glucose oxidase (CNT-GOx) was examined in the presence of 1,4-benzoquinone (BQ). The intrinsic Michaelis parameters of the reaction catalyzed by CNT-GOx were found very close to those of native GOx. However, the Nafion entrapment of CNT-GOx for an electrode resulted in a much lower activity due to the limited availability of the embedded enzyme. Interestingly, kinetic studies revealed that the biofuel cell employing such an enzyme electrode only generated a power density equivalent to <40% of the reaction capability of the enzyme on electrode. It appeared to us that factors such as electron and proton transfer resistances can be more overwhelming than the heterogeneous reaction kinetics in limiting the power generation of such biofuel cells.
碳纳米管（CNTs）已被用于各种生物电化学应用，大概是为了显著提高性能。然而，通常观察到的只是中等程度的结果，尽管已经考虑和提出了许多控制因素，但缺乏系统的评估和验证。在这项研究中，研究了存在 1,4-苯醌（BQ）时，负载在碳纳米管上的葡萄糖氧化酶（CNT-GOx）。CNT-GOx 催化反应的固有米氏参数与天然 GOx 非常接近。然而，由于嵌入酶的可用性有限，用于电极的 Nafion 捕获 CNT-GOx 会导致活性大大降低。有趣的是，动力学研究表明，使用这种酶电极的生物燃料电池仅产生的功率密度相当于酶在电极上的反应能力的 <40%。在我们看来，电子和质子转移电阻等因素可能比非均相反应动力学更能限制这种生物燃料电池的发电能力。
