中文摘要：黄曲霉毒素B1(AFB1)适体的发现，使开发检测AFB1的适体传感器成为了可能。本研究报道了一种直接荧光各向异性(FA)分析法，用来研究适体-AFB1的结合，并用在特定位点具有单季铵罗丹明（TMR）标记的适体来检测AFB1。研究表明，适体探针对其他真菌毒素具有良好的选择性，在复杂样品分析中颇有潜力。适体与黄曲霉毒素亲和力结合的研究，将有助于开发其他基于适体的黄曲霉毒素检测法和传感器。
外文摘要：The discovery of aptamers for aflatoxin B1 (AFB1), one of toxic carcinogens, has allowed to develop aptamer-based sensors and assays for aflatoxin. In this work, we reported a direct fluorescence anisotropy (FA) assay for investigation of aptamer-AFB1 binding and detection of AFB1 with the aptamer having single tetramethylrhodamine (TMR) label on a specific site. From a series of labeling sites of a 50-mer aptamer, we screened out the aptamer with TMR labeling at the 26th T, capable of generating good and large FA-decreasing response to AFB1. By using the T26-labeled 50-mer aptamer probe in FA analysis, we determined the affinity and selectivity of aptamer, and identified the crucial region of aptamer and optimum experimental conditions for strong binding. The aptamer could be further truncated to as short as 26 nucleotides in length, and this shorter aptamer possessed a simple stem-loop secondary structure and retained good binding affinity. Nucleotides in the loop region of the aptamer were conserved and important for affinity recognition. We achieved FA detection of AFB1 with a detection limit about 2 nM by using the TMR-labeled aptamer probe. The cross reactivity of aflatoxin B1, aflatoxin B2, aflatoxin M1, aflatoxin M2, aflatoxin G1, and aflatoxin G2 with aptamer were estimated to be 100%, 61%, 23%, 21%, 6.3%, 6.5%, respectively. The aptamer probe presented good selectivity over other mycotoxins and showed potential in complex sample analysis. This study of affinity binding between aptamer and aflatoxins will be helpful for developing other aptamer-based assays and sensors for aflatoxins.
外文关键词：Aptamer；Fluorescence anisotropy；Fluorescence polarization；Aflatoxin；Affinity ligand；Binding affinity
作者：Sun, LL；Zhao, Q
作者单位：Chinese Acad Sci
期刊名称：TALANTA
期刊影响因子：4.035
出版年份：2018
出版刊次：11
点击下载：用单季铵罗丹明标记的适体，通过直接荧光各向异性方法进行黄曲霉毒素B1检测及亲和结合研究