Aptamer-based lateral flow strip for rapid detection of AFB1 in peanuts, soybeans, corn, and rice

Aflatoxin B1 (AFB1), a Group 1 carcinogenic mycotoxin, poses a significant threat to human health by contaminating crops. It is urgent to establish a simple and rapid detection method to promptly identify the risk of AFB1 residues, thereby mitigating its adverse health effects and reducing economic losses. In this study, a lateral flow strip (LFS) via a high-performance aptamer as the recognition element was developed for the detection of AFB1 in crops. Firstly, Aptamer7 was selected from 8 reported AFB1 aptamers employing molecular dynamics and the SYBR Green I assay, demonstrating good affinity and stability. Subsequently, gold nanoparticles (AuNPs)-based LFS was prepared with the application of Aptamer7. The results showed that the linear detection range was 1–200 ng/mL, with a limit of detection (LOD) of 0.23 ng/mL and strong anti-interference capability. Finally, the method's reliability was evaluated through AFB1-spiked samples. The average recoveries ranged from 92.51 to 119.21 %, with coefficients of variation (CV) between 1.47 and 6.32 % in peanuts, soybeans, corn, and rice. Moreover, the test results generated via the established method showed high consistency with those derived from high-performance liquid chromatography (HPLC), indicating that the LFS provides an alternative and promising strategy for monitoring AFB1 in crops.