College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 210009, China.
School of Environmental and Materials Engineering, College of Engineering, Shanghai Polytechnic University, Shanghai 201209, China.
Anal Chim Acta. 2020 Jul 25;1122:31-38. doi: 10.1016/j.aca.2020.05.009. Epub 2020 May 5.
An upright GO (UGO) modified screen-printed electrode was prepared with the help of the external magnetic field for improving its electrochemical performance. The ratio of GO: Nafion and the magnetic field intensity on the properties of UGO were examined by scanning electron microscope, cyclic voltammetry and electrochemical impedance spectroscopy. The magnetic field intensity does not influence the electron transfer kinetics but increase the number of active sites and therefore enhance the electroactive surface area. In addition, the UGO electrode that was electrodeposited Ni nanoparticles (denotes as Ni NPs/UGO modified electrode) display excellent oxidation towards glycine using chronoamperometry. The Ni NPs/UGO modified electrode indicated an excellent performance for electrochemical COD (chemical oxide demand) analysis with a linear detection range of 0.1-400 mg/L and a lower detection limit of 0.02 mg/L. Moreover, this Ni NPs/UGO modified electrode can be applied to the rapid determination of COD in general real water samples. The results were in agreement with those obtained by using the standard method (ISO 6060).
一种改良的直立式 GO（UGO）修饰丝网印刷电极，在外部磁场的帮助下制备，以改善其电化学性能。通过扫描电子显微镜、循环伏安法和电化学阻抗谱研究了 GO：Nafion 的比例和磁场强度对 UGO 性能的影响。磁场强度不影响电子转移动力学，但增加了活性位点的数量，从而提高了电活性表面积。此外，电沉积了 Ni 纳米粒子的 UGO 电极（表示为 Ni NPs/UGO 修饰电极）在使用计时安培法时对甘氨酸表现出优异的氧化性能。Ni NPs/UGO 修饰电极在电化学 COD（化学需氧量）分析中具有出色的性能，线性检测范围为 0.1-400 mg/L，检测下限低至 0.02 mg/L。此外，该 Ni NPs/UGO 修饰电极可用于快速测定一般实际水样中的 COD。结果与使用标准方法（ISO 6060）获得的结果一致。
