Electrospun nanofiber-based solid-phase extraction coupled with aptamer-mediated FRET assay for detection of aflatoxin M1 in milk

Background Aflatoxin M 1 (AFM 1 ), a highly toxic hydroxylated metabolite of aflatoxin B 1 , is a major contaminant of concern in milk and dairy products, posing significant risks to food safety and public health. Since AFM 1 contamination is closely associated with feed quality, storage conditions, climatic factors, and farm management, reliable AFM 1 detection is important for supporting quality control and safety assessment of dairy products. However, the determination of trace AFM 1 in dairy matrices remains challenging, as complex matrix components may compromise analyte recognition specificity and signal readout. Accordingly, the development of a rapid, sensitive, and matrix-tolerant analytical method is highly desirable for practical AFM 1 monitoring. Results Herein, we developed an integrated analytical strategy combining nanofiber-packed solid-phase extraction (PFSPE) with an aptamer-mediated fluorescence resonance energy transfer (FRET) assay for AFM 1 detection. Four types of polystyrene-polyvinylpyrrolidone (PS-PVP) nanofibers containing different amounts of montmorillonite (MMT) were fabricated by electrospinning and used as sorbents for the PFSPE of AFM 1 . The FRET sensing system was tailored for AFM 1 recognition and enabled rapid signal transduction via target-induced changes in energy transfer efficiency. Both the PFSPE and the FRET-based assay contribute to rapid and accurate AFM 1 determination. Under optimized conditions, the proposed method exhibited satisfactory linearity, recoveries (89.5-95.8%), precisions (RSDs ≤7.4%), and a limit of detection of 0.16 μg/kg. Moreover, the method was successfully applied to the detection of AFM 1 in real milk samples. Significance This work provides an effective analytical strategy for AFM 1 detection by integrating electrospun nanofiber-assisted matrix cleanup and target enrichment with an aptamer-mediated FRET assay, thereby improving the reliability of fluorescence analysis in complex milk matrices and providing a practical platform for rapid screening and preliminary monitoring of AFM 1 contamination in dairy products.