Determination of Fumonisin B₁ by Aptamer-Based Fluorescence Resonance Energy Transfer

Fumonisin FB is produced by Fusarium moniliforme Sheld, of which FB1 is the most common and the most toxic. The establishment of a rapid detection method is an important means to prevent and control FB1 pollution. A highly sensitive fluorescent sensor based on an aptamer for the rapid detection of fumonisin B1 (FB1) in corn was established. In this study, 5-carboxyfluorescein (FAM) was labeled on the aptamer of FB1 (F10). F10 was adsorbed on the surface of graphene oxide (GO) by π-π stacking. The FAM fluorescence signal could be quenched by fluorescence resonance energy transfer between fluorescent molecules and graphene oxide (GO). In the presence of FB1, the binding efficiency of the aptamer to GO was reduced. Therefore, the content of FB1 in corn samples was determined by fluorescence measurements of mixed FAM-labeled F10, GO and corn samples. This method had a good linear relationship in an FB1 concentration range of 0–3000 ng/mL. The equation was y = 0.2576x + 10.98, R2 = 0.9936. The limit of detection was 14.42 ng/mL, and the limit of quantification was 43.70 ng/mL. The recovery of a spiked standard in the corn sample was 89.13–102.08%, and the time of detection was 30 min.