A graphene oxide-based electrochemical sensor for sensitive determination of 4-nitrophenol
A graphene oxide-based electrochemical sensor for sensitive determination of 4-nitrophenol
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DOI：
10.1016/j.jhazmat.2011.11.076
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发表时间：
2012-01-30
影响因子：
13.6
通讯作者：
Liu, Mengqin
中科院分区：
文献类型：
--
作者：
Li, Junhua;Kuang, Daizhi;Liu, Mengqin
制备了一种氧化石墨烯（GO）涂层的玻碳电极（GCE），用于4-硝基苯酚（4-NP）的灵敏测定。采用扫描电镜、原子力显微镜和电化学阻抗谱对氧化石墨烯传感器进行了表征。研究了4-NP在氧化石墨烯薄膜上的电化学行为。在pH为4.8的0.1 M醋酸缓冲液中，4-NP在go修饰的GCE上产生非常敏感和明确的还原峰。结果表明，氧化石墨烯薄膜不仅增加了还原峰电流，而且降低了还原过电位，对4-NP的还原表现出明显的电催化活性。在此基础上，提出了一种直接测定4-NP的电化学方法。计算了转移电子数、转移质子数和标准非均相速率常数等动力学参数，并对各实验参数进行了优化。在最优条件下，还原峰电流随4-NP浓度在0.1 ~ 120 μ M范围内呈线性变化，信噪比为3时的检测限为0.02 μ M。此外，该传感器具有高选择性和长期稳定性。该电化学传感器进一步应用于实际水样中4-NP的检测，显示出简单、灵敏、定量检测4-NP的良好前景。(C) 2011 Elsevier B.V.版权所有
A graphene oxide (GO) film coated glassy carbon electrode (GCE) was fabricated for sensitive determination of 4-nitrophenol (4-NP). The GO-based sensor was characterized by scanning electron microscope, atomic force microscopy and electrochemical impedance spectroscopy. The electrochemical behaviors of 4-NP at the GO-film coated GCE were investigated in detail. In 0.1 M acetate buffer with a pH of 4.8, 4-NP yields a very sensitive and well-defined reduction peak at the GO-modified GCE. It is found that the GO film exhibits obvious electrocatalytic activity toward the reduction of 4-NP since it not only increases the reduction peak current but also lowers the reduction overpotential. Based on this, an electrochemical method was proposed for the direct determination of 4-NP. Various kinetic parameters such as transfer electron number, transfer proton number and standard heterogeneous rate constant were calculated, and various experimental parameters were also optimized. Under the optimal conditions, the reduction peak current varies linearly with the concentration of 4-NP ranging from 0.1 to 120 mu M, and the detection limit is 0.02 mu M at the signal noise ratio of 3. Moreover, the fabricated sensor presented high selectivity and long-term stability. This electrochemical sensor was further applied to determine 4-NP in real water samples, and it showed great promise for simple, sensitive, and quantitative detection of 4-NP. (C) 2011 Elsevier B.V. All rights reserved.