NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China.
NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China.
J Hazard Mater. 2021 Aug 5;415:125584. doi: 10.1016/j.jhazmat.2021.125584. Epub 2021 Mar 4.
Aflatoxins are the most toxic type of mycotoxins, which may cause serious carcinogenesis, teratogenesis, and mutagenesis to humans and animals. In this work, we demonstrate a novel label-free fluorescent aptasensor based on exonuclease-assisted triple recycling amplification for the sensitive detection of aflatoxin B1 (AFB1). With the close cooperation of T7 exonuclease and three elaborately designed hairpin probes, the target AFB1 can perform three consecutive cycles of amplification reactions. In this process, each hairpin probe is fully utilized, and the target AFB1, the secondary target and the tertiary target are recycled, thereby achieving a high amplification. Interestingly and importantly, the secondary and tertiary targets generated by amplification are also excellent DNA template sequences for silver nanoclusters (AgNCs). In the presence of NaBH and AgNO, a great number of DNA-AgNCs are synthesized, thereby producing a strong fluorescent signal. Under optimal conditions, the developed aptasensor exhibited high sensitivity to AFB1 with a low detection limit of 0.19 pg mL and a wide dynamic range of 1 × 10-1 μg mL. In addition, the aptasensor also performed well in the determination of AFB1 in real samples.
黄曲霉毒素是毒性最强的一类真菌毒素，可能对人类和动物造成严重的致癌、致畸和致突变作用。在这项工作中，我们展示了一种基于外切酶辅助的三重循环扩增的新型无标记荧光适体传感器，用于灵敏检测黄曲霉毒素 B1（AFB1）。在 T7 外切酶和三个精心设计的发夹探针的密切配合下，目标 AFB1 可以进行三次连续的扩增反应。在这个过程中，每个发夹探针都得到了充分利用，目标 AFB1、二级目标和三级目标被循环利用，从而实现了高扩增。有趣的是，更重要的是，扩增产生的二级和三级目标也是银纳米簇（AgNCs）的极好的 DNA 模板序列。在 NaBH 和 AgNO 的存在下，大量的 DNA-AgNCs 被合成，从而产生强烈的荧光信号。在最佳条件下，所开发的适体传感器对 AFB1 表现出高灵敏度，检测限低至 0.19 pg mL，动态范围宽达 1×10-1 μg mL。此外，该适体传感器在实际样品中测定 AFB1 时也表现良好。
