Simultaneous electrochemical detection of zinc and copper in fruit juice using Hg/CMWCNTs@ZIF-8 modified glassy carbon electrode

• Published in: Microporous and mesoporous materials Vol. 360; p. 112721
• Main Authors: Qin, Jiangyang, Li, Wanqing, Cai, Ke, Wang, Dandan, Peng, Chenxi, Luo, Lixia, Song, Shizhen, Mei, Yong, Wang, Yong
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.10.2023
• Subjects: CMWCNTs; Electrochemical sensors; Mercury film; Metal ions; ZIF-8; Mercury film; ZIF-8; Electrochemical sensors; CMWCNTs; Metal ions
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2023.112721

Due to their structure and functional characteristics, metal-organic frameworks (MOFs) have unique advantages in the adsorption and pre-enrichment of heavy metal ions. However, most MOFs have poor conductivity, which tremendously limits their application in the field of electrochemical sensing. In this study, a functionalised MOF composite—a carboxylated multi-walled carbon nanotube-zeolitic imidazolate framework material (CMWCNTs@ZIF-8)—was synthesized. An electrochemical sensing platform was constructed using a glassy carbon electrode (GCE) modified by the composite material and mercury film (Hg/CMWCNTs@ZIF-8/GCE). Under optimized conditions, when the concentrations of Zn2+ and Cu2+ were 0.05–1.0 mg L−1, the linear association with their corresponding peak currents was excellent. Furthermore, the detection limits (LODs) for Zn2+ and Cu2+ were 5.23 × 10−3 and 6.52 × 10−3 mg L−1, respectively. Subsequently, the content of Zn2+ and Cu2+ in actual juice beverages was successfully determined. This study not only constructed a novel sensing platform for the simultaneous and sensitive detection of heavy metal ions but also provided a novel method for the detection of Zn2+ and Cu2+ in fruit juice beverages, which is valuable for advancing the application of MOFs as electrochemical sensors. [Display omitted] •ZIF-8-based electrochemical sensor was applied to the detection of Cu2+ and Zn2+.•The fragmentation of ZIF-8 still enhanced the electrochemical performance.•ZIF-8-based sensor had good stability and selectivity for Cu2+ and Zn2+ detection.•This electrochemical method had a wider linear range and a lower detection limit.