A magnetically assisted aptamer-DNAzyme sensing platform coupled with advanced multivariate calibration for highly sensitive detection of aflatoxin B1.

Ultrasensitive detection of aflatoxin B1 (AFB1) in complex food matrices is crucial for global food safety, yet remains challenging due to significant matrix interference and the limited sensitivity of conventional methods. To address this, we developed an integrated magnetic separation-assisted aptamer-DNAzyme fluorescence platform based on streptavidin-modified beads for AFB1 enrichment, DNAzyme-mediated signal amplification, and probe technique-based generalized multivariate standard addition strategy (GMSAprobe), which enables ultrasensitive detection in complex food matrices. Under the optimized experimental parameters, the method achieves a linear range of 0.001-10 ng/mL, limit of detection (LOD) of 0.92 pg/mL, and 98.6-102.9 % spiked recoveries in peanut samples. In conclusion, the cascade signal amplification strategy establishes a new platform for the rapid and sensitive detection of AFB1.