Portable electrochemical aptasensor based on gold-nanoparticles/FeCo-MOFs and PtPd nanoflowers for in site detection of AFB1

Aflatoxin B1 is one of the most toxic carcinogens and has been classified as a group I carcinogen by the International Agency for Research on Cancer. AFB1 is widely distributed in the natural environment and may be present in various grains and products. Therefore, it is significant to establish a strategy for in site detection of AFB1 accurately. Herein, a portable electrochemical aptasensor was developed for accurate detection of AFB1. A screen-printed electrode was selected as the working electrode, which improves the portability and practical application of the aptasensor. The use of gold-nanoparticles/FeCo-MOFs as electrode modification materials improves both the electron transfer efficiency and the large number of connected signal probes. Daisy-like bimetallic PtPd nanoflowers have rich specific surface area, providing numerous sites for loading of the signal molecule thionine. Additionally, the catalytic hairpin assembly cycle amplification strategy was implemented to effectively enhance the sensitivity of the aptasensor. Under optimal conditions, the sensor exhibited a detection range of 0.001–500 ng/mL and a limit of detection of 0.818 pg/mL. The developed aptasensor exhibited positive analytical performance in real samples, quality control samples and toxin samples produced by aspergillus flavus. This work advances the development of portable, sensitive and in site analytical methods, with promising applications in food safety field testing. The specific binding of AFB1 and the aptamer causes CDNA exposure, which in turn triggers the CHA cycle. The generated signal probe Thi/PtPd NFs is added to the AuNPs/FeCo-MOFs modified SPE surface, and the signal change is measured by SWV to detect AFB1. • AuNPs/FeCo-MOFs have excellent conductivity and can connect to DNA. • PtPd NFs can load large amounts of Thi and enhance electrochemical signal. • CHA cycling strategy improves the sensitivity of the aptasensor. • SPE as working electrode improves portability and in site analysis capabilities. • The aptasensor have shown good analytical performance in various real samples.