A novel, ultra-high sensitivity electrochemical aptamer biosensor (EAB) was fabricated by immobilising gold nanoparticles (Au) on a nano-confined interface of N-doped carbon nanofibers/carbon fibers (N-CNFs/CFs). Gold nanoparticle-thiol (Au–S) conjugates, coupled with aptamer-specific recognition technology, were used to immobilise aflatoxin B1 (AFB1). The nanoconfined interface of N-CNFs/CFs provides more binding sites for Au with its unique spatial structure and electroactive surface area, enhancing the electrochemical performance of the matrix. Compared to the existing sensor detection limit, the limit of detection(LOD) of the EAB was approximately 6.4 pg/mL. The dynamic detection ranged from 10.0 to 1.0 × 108 pg/ mL. Furthermore, AFB1 was also successfully detected in Chinese Materia Medica decoction pieces(CMMDP) using the prepared EAB, with recoveries ranging from 96.18 to 112.87%. These results demonstrate the proposed EAB’s potential as a reliable tool for rapid and efficient detection of AFB1 in complex matrices.

Ultra-high sensitivity electrochemical aptamer biosensor based on a carbon nano-confined interface for the detection of aflatoxin B1 in traditional chinese materia medica decoction pieces
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Preparation of MCHAptAuN-CNFsCFs
        2.2 Preparation of AFB1MCHAptAuN-CNFsCFs
        2.3 Preprocessing of real samples
    3 Results and discussion
        3.1 Characterization of the prepared materials
        3.2 Optimization of the AFB1-EAB preparation conditions
    4 Conclusion
    Acknowledgements 
    References

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