A Mechanism of Adsorption of β-Nicotinamide Adenine Dinucleotide on Graphene Sheets: Experiment and Theory
A Mechanism of Adsorption of β-Nicotinamide Adenine Dinucleotide on Graphene Sheets: Experiment and Theory
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DOI：
10.1002/chem.200900399
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发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Boero, Mauro
中科院分区：
文献类型：
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作者：
Pumera, Martin;Scipioni, Roberto;Boero, Mauro
β-烟酰胺腺嘌呤二核苷酸（NAD（+））及其还原形式（NADH）在电化学酶生物传感器和生物燃料电池的开发中起着重要作用。不幸的是，NADH在碳电极处的氧化受到电极钝化和通过电流降低的影响。在这里，我们调查实验和理论上的原因，这种钝化。高分辨率X射线光电子能谱（HR-XPS）、伏安法和电流法表明，吸附发生在石墨烯片的边缘和“边缘样”缺陷上。HR-XPS和从头算分子动力学表明，NAD（+）分子在石墨烯边缘的吸附是由于与羧基等含氧基团的相互作用而发生的，而仅用氢取代的石墨烯边缘容易钝化。
beta-Nicotinamide adenine dinucleotide (NAD(+)) and its reduced form (NADH) play major roles in the development of electrochemical enzyme biosensors; and biofuel cells. Unfortunately, the oxidation of NADH at carbon electrodes suffers from passivation of the electrodes and a decrease in passing currents. Here, we investigate experimentally and theoretically the reasons for such passivation. High-resolution X-ray photoelectron spectroscopy (HR-XPS), voltammetry, and amperometry show that adsorption occurs on the edges and "edge-like" defects of graphene sheets. HR-XPS and ab initio molecular dynamics show that the adsorption of NAD(+) molecules on the edges of graphene happens due to interaction with oxygen-containing groups such as carboxylic groups, while graphene edges substituted only with hydrogen are prone to passivation.