State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Anal Bioanal Chem. 2024 Nov;416(28):6367-6375. doi: 10.1007/s00216-024-05523-2. Epub 2024 Sep 12.
As a kind of mycotoxin, aflatoxin B1 (AFB1), which is often found in agricultural products, poses a threat to human health. Developing a simple sensitive method for AFB1 detection is in great demand. Here, we reported an aptamer-based fluorescence assay for AFB1 detection by using DNAzyme to generate and amplify a signal. We redesigned a pair of DNA sequences, which originated from the anti-AFB1 aptamer and RNA-cleaving DNAzyme 10-23. In the absence of AFB1, the aptamer hybridized with the region of the substrate-binding arm of the DNAzyme, inhibiting the activity of the DNAzyme. In the presence of AFB1, the binding of AFB1 to the aptamer led to the displacement of the DNAzyme from the aptamer. The substrate-binding arm was unblocked, and the activity of the DNAzyme was restored for the hydrolysis of the fluorophore and quencher-labeled substrate, causing a significant fluorescence increase. This assay could detect AFB1 in the dynamic range from 0.98 to 2000 nmol/L with high selectivity, and the detection limit was 0.98 nmol/L. Moreover, the assay was able to detect AFB1 in a complex sample matrix. This work provides a useful tool for the analysis of AFB1.
黄曲霉毒素 B1（AFB1）作为一种真菌毒素，常存在于农产品中，对人类健康构成威胁。因此，开发一种简单、灵敏的 AFB1 检测方法具有重要意义。在这里，我们报道了一种基于适体的荧光分析方法，用于 AFB1 检测，该方法利用 DNA 酶来产生和放大信号。我们重新设计了一对 DNA 序列，它们来源于抗 AFB1 适体和 RNA 切割 DNA 酶 10-23。在没有 AFB1 的情况下，适体与 DNA 酶的底物结合臂区域杂交，抑制 DNA 酶的活性。在存在 AFB1 的情况下，AFB1 与适体的结合导致 DNA 酶从适体上置换。底物结合臂被解锁，DNA 酶的活性得到恢复，用于荧光基团和猝灭剂标记底物的水解，导致荧光显著增加。该分析方法能够在 0.98 至 2000 nmol/L 的动态范围内检测 AFB1，具有高选择性，检测限为 0.98 nmol/L。此外，该分析方法能够检测复杂样本基质中的 AFB1。这项工作为 AFB1 的分析提供了一种有用的工具。
