Sensitive Detection of Aflatoxin B1 in Foods Using Aptasensing Based on FGO-Mediated CdTe QDs

Aflatoxin B1 (AFB1) exhibits high toxicity and has the potential to induce cancer, deformities, and mutations. It is therefore highly desirable that sensitive and straightforward methods for detecting AFB1 be developed. In this study, due to the high specific adsorption capacity of AFB1 aptamers, we applied a sensing strategy based on quantum dots (QDs) and carboxyl-functionalized graphene oxide (FGO) to construct a simple fluorescence quenching platform. FGO and CdTe QDs modified with AFB1 aptamers cause a FRET effect that produces CdTe QDs with yellow-green fluorescence quenching. When AFB1 is present, aptamers form complexes with it and CdTe QDs leave the quenching platform, resulting in fluorescence recovery. In this study, we used a fluorescence aptasensor with a wide detection range of 0.05 to 150 ng/mL and a low limit of detection (LOD) of 8.2 pg/mL. The average recoveries of AFB1 in peanut and pure milk samples ranged from 94.5% to 107.0%. The aptasensor also exhibited the advantages of simple operation, low cost, and good stability. The sensing strategy reported here can thus serve as a potential candidate for the rapid detection of AFB1.