Graphene oxide orientated by a magnetic field and application in sensitive detection of chemical oxygen demand

Xiaolu Li; Donghai Lin; Kunchao Lu; Xue Chen; Shiyu Yin; Yan Li; Zhiyi Zhang; Meihua Tang; Guosong Chen

doi:10.1016/j.aca.2020.05.009

Graphene oxide orientated by a magnetic field and application in sensitive detection of chemical oxygen demand

Anal Chim Acta. 2020 Jul 25:1122:31-38. doi: 10.1016/j.aca.2020.05.009. Epub 2020 May 5.

Authors

Xiaolu Li¹, Donghai Lin², Kunchao Lu¹, Xue Chen¹, Shiyu Yin¹, Yan Li¹, Zhiyi Zhang¹, Meihua Tang³, Guosong Chen⁴

Affiliations

¹ College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 210009, China.
² School of Environmental and Materials Engineering, College of Engineering, Shanghai Polytechnic University, Shanghai 201209, China. Electronic address: dhlin@sspu.edu.cn.
³ School of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 210009, China.
⁴ College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 210009, China. Electronic address: gschen@njtech.edu.cn.

PMID: 32503741
DOI: 10.1016/j.aca.2020.05.009

Abstract

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).

Keywords: COD; Electrochemical impedance spectroscopy; Graphene oxide; Ni nanoparticles; Screen-printed electrode.