Nitrite is commonly found in various aspects of daily life, but its excessive intake poses health risks like blood oxygen transport impairment and cancer risks. Accurate detection of nitrite is crucial for preventing its potential harm and ensuring public health. In this work, Cu–Co bimetallic nanoparticles (NPs) incorporated nitrogen-doped carbon dodecahedron (Cu/ Co@N–C/CNTs-X, where X denotes the carbonization temperatures) are synthesized by facile carbonization of CuO@ZIF- 67 composites. Cu and Co NPs are uniformly embedded in the carbon dodecahedron decorated by carbon nanotubes (CNTs) without agglomeration. Combining the superior catalytic from Cu and Co NPs with the electrical conductivity and stability from the carbon frameworks, the Cu/Co@N–C/CNTs-600 composite as catalyst detected nitrite concentrations ranging from 1 to 5000 μM, with sensitivity values of 0.708 μA μM–1 cm– 2, and a detection limit of 0.5 μM. Moreover, this sensor demonstrated notable selectivity, stability and reproducibility. The design of Cu/Co@N–C/CNTs-X catalysts prepared in this study can be used as an attractive alternative in the fields of food quality and environmental detection.

Hierarchical bimetallic nanoparticles embedded nitrogen-doped carbon derived from ZIF-67 composites for efficient electrochemical nitrite sensing
    Abstract
    1 Introduction
    2 Results and discussion
        2.1 Preparation and structural characterization
        2.2 Electrochemical performance of the different modified sensors
        2.3 Selectivity, reproducibility, and stability
    3 Conclusion
    Acknowledgements 
    References

• Jingwen Zhao(School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225009, Jiangsu, China)
• Wenzhuo Sun(School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225009, Jiangsu, China)
• Huan Pang(School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225009, Jiangsu, China)
• Xiaotian Guo(School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225009, Jiangsu, China, College of Tourism and Culinary Science, Key Laboratory of Chinese Cuisine Intangible Cultural Heritage Technology Inheritance, Ministry of Culture and Tourism, Yangzhou University, Yangzhou 225127, Jiangsu, China)
• Jing Wang(College of Tourism and Culinary Science, Key Laboratory of Chinese Cuisine Intangible Cultural Heritage Technology Inheritance, Ministry of Culture and Tourism, Yangzhou University, Yangzhou 225127, Jiangsu, China)
• Jizhou Jiang(School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430205, Hubei, China)