Qu Chenling, Zhao Luyang, He Xing, Yu Songcheng, Wei Min
College of Food Science and Technology, Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, Henan University of Technology, No. 100 Lianhua Street, Zhengzhou, 450001, Henan, People's Republic of China.
College of Public Health, Zhengzhou University, Zhengzhou, 450001, People's Republic of China.
Anal Bioanal Chem. 2021 Nov;413(26):6677-6685. doi: 10.1007/s00216-021-03635-7. Epub 2021 Sep 6.
A magnetic beads (MBs)-assisted fluorescence aptasensing approach based on dual DNA tweezers and magnetic separation was established for the detection of ochratoxin A (OTA) and fumonisin B (FB). A dual DNA tweezers structure with four ends linked with fluorophores (FAM, ROX) and quenchers (BHQ, BHQ) was designed, and produced the high initial fluorescence signals because of the long spatial distance between FAM and BHQ, ROX, and BHQ. Bio-aptamer/anti-aptamer of OTA and bio-aptamer/anti-aptamer of FB were respectively annealed to form dsDNA, and immobilized to MBs coated with streptavidin (SA). With the existence of OTA and FB, OTA and FB preferentially bound with their respective bio-aptamers, which made anti-aptamers dissociate from dsDNA coupled on MBs. After magnetic separation, the dissociated anti-aptamers reacted with dual DNA tweezers, respectively, which made DNA tweezers close and the fluorescence was quenched. The linear ranges of approach for OTA and FB detection were 0.05-20 ng/mL and 0.1-40 ng/mL, respectively. The limit of detection for OTA and FB was 0.029 ng/mL and 0.061 ng/mL. The prepared MBs-assisted fluorescence aptasensing approach was applied to detect OTA and FB in spiked red wine and corn samples, which showed good recoveries between 92 and 106%.
建立了一种基于双DNA镊子和磁分离的磁珠（MBs）辅助荧光适配体传感方法，用于检测赭曲霉毒素A（OTA）和伏马菌素B（FB）。设计了一种双DNA镊子结构，其四个末端分别连接有荧光团（FAM、ROX）和猝灭剂（BHQ、BHQ），由于FAM与BHQ、ROX与BHQ之间的空间距离较长，产生了较高的初始荧光信号。OTA的生物适配体/抗适配体和FB的生物适配体/抗适配体分别退火形成双链DNA，并固定在涂有链霉亲和素（SA）的磁珠上。在存在OTA和FB的情况下，OTA和FB优先与其各自的生物适配体结合，这使得抗适配体从偶联在磁珠上的双链DNA上解离。磁分离后，解离的抗适配体分别与双DNA镊子反应，使DNA镊子闭合，荧光猝灭。该方法检测OTA和FB的线性范围分别为0.05 - 20 ng/mL和0.1 - 40 ng/mL。OTA和FB的检测限分别为0.029 ng/mL和0.061 ng/mL。所制备的磁珠辅助荧光适配体传感方法应用于加标红酒和玉米样品中OTA和FB的检测，回收率在92%至106%之间，显示出良好的回收率。
