Contamination of food with heavy metal ions and nitrites poses a serious threat to human health. Consequently, the development of fast and sensitive platforms for detecting these contaminants is urgently required. In this paper, a novel MnMgFe- LDHs/DC sensor is constructed based on a simple strategy, in which MnMgFe layered double hydroxide (LDHs) is used as a metal precursor, and a unique "island bridge" carbon network structure is generated by its pyrolysis with ZIF-8@B, N-WMCNTs. The electrical conductivity was enhanced, and a large electroactive surface area was provided for the MnMgFe- LDHs/DC. The electrochemical properties of Pb2+, Cd2+ and nitrite were investigated using this electrode as a working electrode. Under optimized conditions, the sensing platform exhibited a wide linear range with the Pb2+, Cd2+, and NO2 − limits of detection of 46.16 nM, 59.25 nM, and 0.083 μM, respectively. Of particular note is that this sensing platform exhibits outstanding anti-interference capabilities. It can precisely and efficiently conduct the detection of nitrite and heavy metal ions in pickled foods.

MnMgFe-LDHsZIF-8B, N-WMCNTs nanocomposites for efficient electrochemical detection of nitrite and heavy metal ions
    Abstract
    1 Introduction
    2 Experimental section
        2.1 Instruments and reagents
            2.1.1 Instruments and reagents
        2.2 Preparation of MnMgFe-LDHsDC electrode
        2.3 Electrochemical performance test
        2.4 Processing of real samples
    3 Results and discussion
        3.1 Morphology and structure
        3.2 Electrochemical performance characterization
        3.3 Optimization of experimental conditions
        3.4 Electrochemical detection of Pb2+, Cd2+, and NO2−
        3.5 Repeatability, reproducibility, and interference research
        3.6 Actual sample detection of electrochemical sensors
    4 Conclusion
    Acknowledgements 
    References

• Xue Du(Department of Chemistry, Yanbian University, Park Road 977, Yanji 133002, People’s Republic of China)
• Tong Han(Department of Chemistry, Yanbian University, Park Road 977, Yanji 133002, People’s Republic of China)
• Long‑Yue Meng(Department of Chemistry, Yanbian University, Park Road 977, Yanji 133002, People’s Republic of China) Corresponding author
• Biao Jin(Analysis and Test Center, Yanbian University, Park Road 977, Yanji 133002, Jilin Province, People’s Republic of China)
• Lian‑Hua Han(Department of Chinese Traditional Medicine, Medical College, Yanbian University, Park Road 977, Yanji 133002, Jilin Province, People’s Republic of China)