Abstract：
A fluorescence biosensor for determination of aflatoxin B1 (AFB1) based on polydiacetylene (PDA) liposomes and exonuclease III (EXO III)-assisted recycling amplification was developed. The AFB1 aptamer partially hybridizes with complementary DNA (cDNA), which is released upon recognition of AFB1 by the aptamer. Subsequently, the cDNA hybridizes with hairpin H to form double-stranded DNA that undergoes digestion by EXO III, resulting in the cyclic release of cDNA and generation of capture DNA for further reaction. The capture DNA then hybridizes with probe modified on PDA liposomes, leading to aggregation of liposomes and subsequent fluorescence production. This strategy exhibited a limit of detection of 0.18 ng/mL within the linear range 1-100 ng/mL with a determination coefficient > 0.99. The recovery ranged from 92.81 to 106.45%, with relative standard deviations (RSD) between 1.73 and 4.26%, for corn, brown rice, peanut butter, and wheat samples. The stability, accuracy, and specificity of the method demonstrated the applicability for real sample analysis.
摘要：
开发了一种基于聚二乙炔（PDA）脂质体和外切核酸酶III（EXOIII）辅助回收扩增的荧光生物传感器，用于测定黄曲霉毒素B1（AFB1）。AFB1适体与互补DNA（cDNA）部分杂交，其在通过适体识别AFB1时释放。随后，cDNA与发夹H杂交形成双链DNA，经过EXOIII消化，导致cDNA的循环释放和捕获DNA的产生用于进一步反应。然后捕获DNA与在PDA脂质体上修饰的探针杂交，导致脂质体聚集和随后的荧光产生。该策略在1-100ng/mL的线性范围内表现出0.18ng/mL的检出限,测定系数>0.99。回收率为92.81-106.45%,相对标准偏差(RSD)在1.73和4.26%之间，对于玉米，糙米,花生酱,和小麦样本。的稳定性,准确度,方法的特异性和特异性证明了实际样品分析的适用性。
