Determination of aflatoxin B1 in Pixian Douban based on aptamer magnetic solid-phase extraction

Aflatoxin B1 (AFB(1)) is considered as the most prevalent and toxic mycotoxin in food, and is the indispensable index in the monitoring of Pixian Douban, a traditional chinese fermented bean paste from Sichuan. However, the effeciency of AFB(1) detection in Pixian Douban is influenced by the traditional extraction, which is usually complex and time consuming. Therefore, an aptamer-based magnetic solid-phase extraction method was designed for the pretreatment of AFB(1) in this sample, for which Fe(3)O(4) was synthesized via the solvothermal method and then a Fe(3)O(4)@SiO(2)–NH(2) with a core–shell structure was prepared, followed by an AFB(1)-aptamer attachment. The validation was performed via an enzyme-linked immunosorbent assay and compared with HPLC-MS/MS. The linearity range of this method was 0.5–2.0 ng mL (−1) with R(2) of 0.981, and recoveries of AFB(1) ranged from 80.19% to 113.92% with RSDs below 7.28% with no significant differences compared to HPLC-MS/MS. The three-time reusability efficiencies of aptamer-MNPs were averaged at 78.24%. The results proved that aptamer-MNPs were high-performance adsorbents for extracting and enriching AFB(1), facilitating quick and effective detection of AFB(1) in Pixian DouBan samples.