Development of an unlabeled aptamer-based fluorimetric method for aflatoxin B detection combined with nanofiber-packed solid-phase extraction.

A novel unlabeled aptamer-based fluorimetric method combined with fiber-packed solid-phase extraction (FPSPE) was developed for the detection of aflatoxin B (AFB). Polystyrene-cellulose acetate butyrate-montmorillonite K-10 (PS-CAB-MMTK-10) nanofibers were prepared by electrospinning method and used as adsorbent for solid phase extraction of AFB. Then the types of nanofibers, types of activation solution, pH value of sample, types of eluent, amount of packed fibers, eluent volume and extraction time were studied and optimized. Under optimal conditions, the method was shown a preferable linear relationship in the range of 0.5-200 nM, and the limit of detection (LOD) was 0.3 nM, and the recovery rate was 85.1-91.2 %. This proposal method realized the detection of AFB based on the different fluorescence intensities caused by the different contents of the target substance in the detection system. The method does not require covalent labeling aptamers, and it is simple to operate to apply to the rapid detection of AFB in food.