Kamata Tomoyuki, Kato Dai, Niwa Osamu
National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
Nanoscale. 2019 May 30;11(21):10239-10246. doi: 10.1039/c9nr01569h.
Carbon materials containing nitrogen have been extensively studied as electrode materials for use in non-platinum cathodes of fuel cells due to their high electrocatalytic activity for oxygen reduction. The activity is strongly dependent on the structure of surface nitrogen-containing functional groups. Carbon film containing nitrogen is also suitable for analytical applications because of its low background noise and its electrocatalytic activity, which is superior to that of pure carbon film. Here, we fabricated sputter-deposited nanocarbon film with a nitrogen-containing group and estimated the efficacy of a surface nitrogen-containing group for detecting biomolecules. Two types of carbon films, one rich in graphite-like nitrogen-containing bonds and the other rich in pyridine-like bonds, were successfully fabricated without changing their nitrogen concentration, sp2/sp3 ratio or surface flatness. The carbon film rich in pyridine-like bonds shows a positive oxygen reduction peak of about 250 mV compared with pure carbon film and is also 200 mV more positive compared with film with graphite-like nitrogen-containing bonds. This indicates that pyridine-like bonds contribute more effectively to electrocatalytic activity than graphite-like nitrogen-containing bonds. For detecting biomolecules, carbon film rich in pyridine-like bonds also exhibits more negative peak potentials for the oxidation of NADH and l-ascorbic acid, suggesting that carbon film rich in pyridine-like bonds will show improved performance for detecting electroactive biomolecules.
含氮碳材料因其对氧还原具有高电催化活性，作为燃料电池非铂阴极的电极材料已得到广泛研究。该活性强烈依赖于表面含氮官能团的结构。含氮碳膜因其低背景噪声和电催化活性，也适用于分析应用，其电催化活性优于纯碳膜。在此，我们制备了含氮基团的溅射沉积纳米碳膜，并评估了表面含氮基团对生物分子检测的功效。成功制备了两种碳膜，一种富含类石墨氮键，另一种富含吡啶类键，且未改变其氮浓度、sp2/sp3 比或表面平整度。与纯碳膜相比，富含吡啶类键的碳膜显示出约 250 mV 的正氧还原峰，与含类石墨氮键的膜相比也正 200 mV。这表明吡啶类键比类石墨氮键对电催化活性的贡献更有效。对于生物分子检测，富含吡啶类键的碳膜对 NADH 和 l -抗坏血酸的氧化也表现出更负的峰电位，这表明富含吡啶类键的碳膜在检测电活性生物分子方面将表现出更好的性能。
