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.