1,2-萘醌修饰的碳纳米管对β-烟酰胺腺嘌呤二核苷酸电化学氧化的催化作用

Electrocatalytic Activities of 1,2-Naphthoquinone Modified Carbon Nanotube to the Electrochemical Oxidation of β-Nicotinamide Adenine Dinucleotide

将具有电活性的1,2-萘醌(1,2-naphthoqu inone,Nq)分子修饰到碳纳米管(CNT)表面形成Nq-CNT纳米复合体,用紫外可见(UV-V is)和红外光谱等方法对Nq-CNT进行了表征,结果表明Nq不仅能快速、有效地修饰到CNT表面,而且还能有效地改善CNT在水溶液中的分散性能。循环伏安结果显示,与GC电极相比,CNT能显著提高Nq的氧化还原峰电流,其伏安曲线上表现出一对几乎对称的氧化还原峰,式量电位E0′几乎不随扫速而变化。进一步的实验结果表明,Nq和CNT对β-烟酰胺腺嘌呤二核苷酸(NADH)的电化学氧化具有协同催化作用,与CNT或Nq相比,Nq-CNT具有较高的电催化活性,能使其氧化过电位降低超过510 mV。本研究对碳纳米管功能化方法具有简单、电极制作容易以及催化效率高等优点。

It was reported that carbon nanotube （CNT） was functionalized with the electroactive species of 1,2-naphthoquinone （Nq） by a method of adsorption to form Nq-CNT nanocomposite. The Nq-CNT was characterized by spectroscopic techniques, for example ultraviolet-visible （UV-Vis）, Fourier transform infrared （FTIR） and scanning electron microscopy （SEM） etc. , and the results show that Nq can rapidly and effectively be adsorbed on the surface of CNT with high stability. Moreover, it is shown that the dispersion ability of CNT in aqueous solution has a significantly improvement after CNT functionalized with Nq. The Nq- CNT/glasssy carbon （GC） electrode was fabricated by modifying Nq-CNT nanocomposite on the GC electrode surface and its electrochemical properties were investigated by voltammetry, which indicate that CNT could improve the electrochemical behavior of Nq and greatly enhanced its redox peak currents. The Nq-CNT/GC electrode exhibited a pair of well-defined and nearly symmetrical redox peaks with the formal potential of - 87.3 ± 4.5 mV （vs. SCE,0.1 mol/L PBS, pH 7.0）, which was almost independent on the scan rates. The experimental results also demonstrate that Nq and CNT can synergistically catalyze the electrochemically oxidation of β-nicotinamide adenine dinucleotide （NADH） and Nq-CNT exhibits a high performance with lowering the overpotential of more than 510 mV. The present method has several advantages, such as rapid and facile CNT functionalization, easy electrode fabrication and high electrocatalytic activity etc.