Mesoporous carbon decorated with MIL-100(Fe) as an electrochemical platform for ultrasensitive determination of trace cadmium and lead ions in surface water

• Published in: Ecotoxicology and environmental safety 2022-09, Vol.243, p.113987, Article 113987
• Main Authors: Zhu, Yelin, Zhou, Shuxing, Zhu, Jian, Wang, Ping, Wang, Xinzhong, Jia, Xiuxiu, Wågberg, Thomas, Hu, Guangzhi
• Format: Article
• Language: English
• Subjects: Cadmium - analysis; Carbon - chemistry; Cd(II); Drinking Water - analysis; Electrochemical sensor; Electrodes; Ions - chemistry; Lead - analysis; Mesoporous carbon; MIL-100(Fe); Pb(II); Reproducibility of Results; Simultaneous determination
• ISSN: 0147-6513; 1090-2414; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.113987

In this work, MIL-100(Fe)-decorated mesoporous carbon powders (MC@MIL-100(Fe)) were prepared by in situ growth of MIL-100(Fe) on the surface of ZIF-8 framework-based mesoporous carbons (MC). The hybrid material was characterized using SEM equipped with EDS mapping for morphology investigation, X-ray photoelectron spectroscopy for chemical valence analysis, and X-ray diffraction for crystal structure determination. The developed sensor separated from the traditional bismuth film decoration, and simultaneously, MC@MIL-100(Fe) was applied for the first time to electrochemically detect trace amounts of Pb(II) and Cd(II). The fabricated MC@MIL-100(Fe)-based electrochemical sensor showed excellent response to the target analytes at –0.55 and − 0.75 V for lead and cadmium ions, respectively. By adjusting some measurement parameters, that is, the loading concentration of MC@MIL-100(Fe), acidity of the HAc-NaAc buffer (ABS), deposition potential, and deposition time, the analytical performance of the proposed electrochemical sensor was examined by exploring the calibration curve, repeatability, reproducibility, stability, and anti-interference under optimized conditions. The response current of the proposed MC@MIL-100(Fe) electrochemical sensor showed a well-defined linear relationship in the concentration ranges of 2–250 and 2–270 μg·L−1 for Cd(II) and Pb(II), respectively. In addition, the detection limits of the sensor for Cd(II) and Pb(II) were 0.18 and 0.15 μg L−1, respectively, which are well below the World Health Organization (WHO) drinking water guideline value. The MC@MIL-100(Fe) can be potentially used as an electrochemical platform for monitoring heavy metals in surface water, with satisfactory results. [Display omitted] •A noval heavy metal ion sensor based on MC@MIL-100 (Fe) was developed.•The incorporation of MC material reduced the background current of the detection.•The LOD of the sensor for Pb(II) and Cd(II) as low as 0.15 and 0.18 μg·L−1.•MC@MIL-100 (Fe) based sensor is expected to be used in actual water samples.