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.
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.
J Environ Sci (China). 2020 Nov;97:19-24. doi: 10.1016/j.jes.2020.04.016. Epub 2020 Jun 1.
Bisphenol A (BPA) is one of the environmental endocrine disruptors (EDCs), and BPA contamination in environment can cause high risks to human health. Rapid determination of BPA on sites is in high demand in environmental analysis. Taking advantage of aptamers as affinity ligands and fluorescence anisotropy (FA) analysis, we developed a simple and rapid FA assay for BPA by employing a single tetramethylrhodamine (TMR) labeled short 35-mer DNA aptamer against BPA. The assay is based on the BPA-binding induced conformation change of TMR-labeled aptamer and alteration of interaction between TMR and guanine bases, resulting in change of FA signals. We screened the FA change of aptamer probes having TMR label on a specific site of the aptamer upon BPA addition. The aptamer with a TMR label on the 22nd T base showed large FA-decreasing response to BPA and maintained good binding affinity to BPA. By using this TMR-labeled aptamer, we achieved FA detection of BPA with a detection limit of 0.5 μmol/L under the optimized conditions. This assay was selective towards BPA and enabled the detection of BPA spiked in tap water sample, showing the potential applications on water samples.
双酚 A（BPA）是环境内分泌干扰物（EDCs）之一，环境中的 BPA 污染会对人类健康造成高风险。因此，在环境分析中，现场快速测定 BPA 成为了一项迫切的需求。本研究利用适体作为亲和配体和荧光各向异性（FA）分析，开发了一种简单、快速的 FA 分析方法，用于检测 BPA。该方法基于 TMR 标记的短 35 -mer DNA 适体与 BPA 的结合诱导构象变化，以及 TMR 与鸟嘌呤碱基之间相互作用的改变，从而导致 FA 信号的变化。我们筛选了在 BPA 加入时 TMR 标记在适体特定位置的适体探针的 FA 变化。在第 22 位 T 碱基上带有 TMR 标记的适体表现出对 BPA 的较大 FA 减少响应，并保持对 BPA 的良好结合亲和力。使用这种 TMR 标记的适体，我们在优化条件下实现了 BPA 的 FA 检测，检测限为 0.5 μmol/L。该测定方法对 BPA 具有选择性，并能够检测自来水中添加的 BPA，显示出在水样检测方面的应用潜力。
