Efficient Direct Electron Transfer with Enzyme on a Nanostructured Carbon Film Fabricated with a Maskless Top-Down UV/Ozone Process
Efficient Direct Electron Transfer with Enzyme on a Nanostructured Carbon Film Fabricated with a Maskless Top-Down UV/Ozone Process
复制标题
DOI：
10.1021/ja108614d
复制
发表时间：
2011-04-06
影响因子：
15
通讯作者：
Niwa, Osamu
中科院分区：
文献类型：
--
作者：
Ueda, Akio;Kato, Dai;Niwa, Osamu
我们开发了一种具有刺状表面纳米结构的新型碳膜电极材料，以实现与酶的高效直接电子转移(DET)，这对各种酶生物传感器以及用于生物燃料电池的阳极或阴极非常重要。纳米结构是在没有掩膜的情况下用UV/臭氧处理制备的，原子力显微镜测量证实得到的纳米结构的高度通常为2-3.5 nm。X射线光电子能谱和透射电子显微镜表明，采用电子回旋共振溅射法制备的纳米碳膜，其刻蚀速率随纳米量级的不同而不同，可以形成这些纳米结构。这些结构不能用其他碳膜实现，如掺硼金刚石、玻璃碳、基于旋涂聚酰亚胺或真空沉积的酞菁薄膜的热解聚合物，或类钻石碳膜，因为这些碳膜具有相对均匀的结构或微米级的晶体结构。将胆红素氧化酶物理吸附在纳米碳膜表面后，DET催化电流放大倍数是原碳膜的30倍。这种高效的DET不能通过改变平板碳表面的亲水性来实现，这表明DET是通过形成具有亲水表面的纳米结构来加速的。用细胞色素c也能观察到有效的DET。
We have developed a new carbon film electrode material with thornlike surface nanostructures to realize efficient direct electron transfer (DET) with enzymes, which is very important for various enzyme biosensors and for anodes or cathodes used in biofuel cells. The nanostructures were fabricated using UV/ozone treatment without a mask, and the obtained nanostructures were typically 2-3.5 nm high as confirmed by atomic force microscopy measurements. X-ray photoelectron spectroscopy and transmission electron microscopy revealed that these nanostructures could be formed by employing significantly different etching rates depending on nanometer-order differences in the local sp(3) content of the nanocarbon film, which we fabricated with the electron cyclotron resonance sputtering method. These structures could not be realized using other carbon films such as boron-doped diamond, glassy carbon, pyrolyzed polymers based on spin-coated polyimide or vacuum-deposited phthalocyanine films, or diamond-like carbon films because those carbon films have relatively homogeneous structures or micrometer-order crystalline structures. With physically adsorbed bilirubin oxidase on the nanostructured carbon surface, the DET catalytic current amplification was 30 times greater than that obtained with the original carbon film with a flat surface. This efficient DET of an enzyme could not be achieved by changing the hydrophilicity of the flat carbon surface, suggesting that DET was accelerated by the formation of nanostructures with a hydrophilic surface. Efficient DET was also observed using cytochrome c.