State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122, Jiangsu, China.
College of Food Engineering, Anhui Science and Technology University, Fengyang, 233100, Anhui, China.
Anal Bioanal Chem. 2019 Feb;411(5):1107-1115. doi: 10.1007/s00216-018-1540-6. Epub 2019 Jan 5.
Aflatoxin B (AFB) is the most toxic mycotoxin of the aflatoxins (AFs) and shows carcinogenic, teratogenic and mutagenic effects in humans and animals. AFB is widely seen in cereal products such as rice and wheat. This research proposed a low-cost, high-sensitivity fluorescence polarization (FP) assay for detection of AFB using aptamer biosensors based on graphene oxide (GO). The aptamers labelled with fluorescein amidite (FAM) were adsorbed on the surface of GO through π-π stacking and electrostatic interaction, thus forming aptamer/GO macromolecular complexes. Under these conditions, the local rotation of fluorophores was limited and the system had a high FP value. When there was AFB in the system, aptamers were dissociated from the GO surface and combined with AFB owing to their specificity to form aptamer/AFB complexes. As a result, large changes were observed in the molecular weights of aptamers before, and after, the combination, therefore leading to the apparent changes in FP value. The results showed that when only 10 nM of aptamer was used, the changes in FP and the AFB concentration had a favourable linear relationship within 0.05 to 5 nM of AFB, and the lowest detection limit (LOD) was 0.05 nM. In addition, the recoveries of rice sample extract ranged from 89.2% to 112%. The method is simple, highly sensitive, cost-efficient and shows potential application prospects.
黄曲霉毒素 B（AFB）是黄曲霉毒素（AFs）中最具毒性的一种，对人类和动物具有致癌、致畸和致突变作用。AFB 广泛存在于谷物产品中，如大米和小麦。本研究提出了一种基于氧化石墨烯（GO）的适体生物传感器的低成本、高灵敏度荧光偏振（FP）检测方法，用于检测 AFB。用荧光素亚胺（FAM）标记的适体通过π-π堆积和静电相互作用吸附在 GO 表面上，从而形成适体/GO 大分子复合物。在这些条件下，荧光团的局部旋转受到限制，系统具有高 FP 值。当系统中有 AFB 时，适体由于其特异性而从 GO 表面解离并与 AFB 结合，形成适体/AFB 复合物。结果表明，当仅使用 10 nM 的适体时，在 0.05 至 5 nM 的 AFB 范围内，FP 值的变化与 AFB 浓度呈良好的线性关系，最低检测限（LOD）为 0.05 nM。此外，大米样品提取物的回收率在 89.2%至 112%之间。该方法简单、灵敏、经济，具有潜在的应用前景。
