1673-159X

CN 51-1686/N

基于铽离子的非标记核酸适配体传感器检测黄曲霉毒素B1

A Label-free Aptasensor Based on Tb3+ of Aflatoxin B1

  • 摘要: 黄曲霉毒素B1(aflatoxin B1, AFB1)具有致癌、致畸和致突变效应,被国际癌症研究机构(IARC)列为一类致癌物,对消费者健康有巨大威胁。当Tb3+单独存在溶液中时,检测不到其特征荧光;当Tb3+与单链核酸结合后可形成络合物,使得Tb3+特征荧光显著增强;当加入靶分子AFB1后,由于AFB1可与核酸适配体结合,从而引起构象变化形成双链,Tb3+不能与双链核酸结合发光,使得荧光增强得到抑制。本研究基于上述原理构建了一种基于稀土铽离子(Tb3)特征荧光效应的非标记核酸适配体传感器,可实现对 AFB1的均相快速检测。该方法利用荧光信号的变化对AFB1进行定量分析,检测限为1.84 ng/mL。由于核酸适配体对靶分子识别具有专一性,可以在复杂的基质中准确区分检测出AFB1及其他真菌毒素。在回收率实验中核酸适配体传感器得到的回收率为 95.94%~107.12%,验证了该方法的有效性。该检测方法不需要对核酸进行修饰标记,可节约成本,检测全过程操作简单,且不需要分离,在一个洁净的离心管内即可完成,可实现对AFB1的均相检测。

     

    Abstract: Aflatoxin B1 (AFB1) has carcinogenic, teratogenic and mutagenic effects. It has been categorized as a group I carcinogen by the international agency for research on cancer (IARC). Thus, AFB1 poses a great threat to consumers' health. When Tb3+ was alone in solution, its characteristic fluorescence could not be detected. Nevertheless, the single-stranded oligonucleotides can greatly enhance the emission of Tb3+ in solution. The target AFB1 can bind to aptamer, thus causing conformational change of aptamer to form a double chain. The duplexes can significantly inhibit the emission of Tb3+. Based on above principles, this study constructed a fluorescence characteristic of rare earth terbium ion (Tb3+) unlabeled nucleic acid aptamer sensor can realize homogeneous and rapid detection of AFB1. According to this principle, this method achieves quantitative analysis of AFB1 via the change of fluorescence signal. The LOD was 1.84 ng/mL. Due to the specificity of nucleic acid aptamer in target molecule recognition, AFB1 and other mycotoxins can be accurately identified and detected in complex matrix. Moreover, the recovery rate obtained by nucleic acid aptamer sensor in the experiment was 95.94%~107.12%, which verified the effectiveness of this method. This method does not need label aptamers so as to save cost. The whole process of detection is easy to operate without separation procedures. The detection can be completed in a clean centrifuge tube, which can realize homogeneous analysis of AFB1.which can realize homogeneous analysis of AFB1.

     

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