中文摘要：黄曲霉毒素B1（AFB1）是毒性最强的霉菌毒素之一，引起人们对健康和食品安全的极大关注。一种具有茎环结构的抗AFB1适配子显示出与AFB1的亲和力很高，有望改进AFB1的检测方法。本研究基于适体的结构转换特性，报道了一种适体荧光分析法，用来检测AFB1。研究表明，该方法能检测复杂基质，如稀释葡萄酒样品和玉米粉样品中的AFB1。该适体荧光分析测定AFB1的方法具有广泛应用的潜力。
外文摘要：Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins and draws great concern in health and food safety. A DNA aptamer against AFB1 having a stem-loop structure shows high binding affinity to AFB1 and promise in assay development for AFB1 detection. Based on the structure-switching property of the aptamer, we report an aptamer fluorescence assay for AFB1 detection. Aptamer with fluorescein (FAM) label at 5′ end was used as affinity ligand, while its short complementary DNA (cDNA) with BHQ1 (black hole quencher 1) label at 3′ end was used as a quencher. In the absence of AFB1, FAM-labeled aptamer hybridized with BHQ1-labeled cDNA, forming a duplex of cDNA and aptamer, resulting in fluorescence quenching of FAM. When AFB1 bound with aptamer, the BHQ1-labeled cDNA was displaced from aptamer, causing fluorescence restoration of FAM. We tested a series of FAM-labeled aptamers and BHQ1-labeled cDNAs with different lengths. The lengths of the aptamer stem and the cDNA, Mg2+ in binding buffer, and temperature had significant influence on the performance of the assay. Under optimized conditions, we achieved sensitive detection of AFB1 by using a 29-mer FAM-labeled aptamer and a 14-mer BHQ1-labeled cDNA, and the detection limit of AFB1 reached 0.2 nM. The maximum fluorescence recovery rate of FAM-labeled aptamer caused by AFB1 was about 69-fold. This method enabled the detection of AFB1 in complex sample matrix, e.g., diluted wine samples and maize flour samples. This aptamer-based fluorescent assay for AFB1 determination shows potential for broad applications.
外文关键词：Aptamer；Aflatoxin；Fluorescence；Sensor；Affinity binding
作者：Li, YP；Sun, LL；Zhao, Q
作者单位：Chinese Acad Sci
期刊名称：ANALYTICAL AND BIOANALYTICAL CHEMISTRY
期刊影响因子：3.125
出版年份：2018
出版刊次：24
点击下载：用荧光素标记的适配子与黑孔剂1标记的互补DNA研制适体荧光开关分析法，检测黄曲霉毒素B1