Key Laboratory of Natural Resources of Changbai Mountain and Functional Molecules, Yanbian University, Ministry of Education, Yanji 133002, China.
Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Food Chem. 2018 May 30;249:45-50. doi: 10.1016/j.foodchem.2017.12.087. Epub 2017 Dec 30.
This paper describes an aptamer/gold nanoparticle-based assay for ochratoxin A (OTA) detection. This assay is based on the use of an aptamer labeled with carboxyfluorescein (FAM) at its 5'-end and gold nanoparticles (AuNPs) that act as quenchers of fluorescence. When OTA is absent in the system, the fluorescently labeled aptamers are adsorbed on the surface of AuNPs. The fluorescence signal of the fluorescein-labeled OTA aptamer generated is quenched by the fluorescence resonance energy transfer effect of AuNPs. When OTA is present in the system, the fluorescently labeled aptamer binds to OTA and forms a folded structure, which can resist the adsorption of AuNPs. Thus, the fluorescent signal can be retained. The detection limit of this sensing platform is 5 nM, and the linear detection range is 10-1000 nM (R = 0.994). The procedure was validated by the quantitation of OTA in spiked ginger powder samples and were found to be free of interference by the sample matrix. The recoveries and the relative standard deviation varied from 89.0% to 117.8% and from 1.9% to 6.3%, respectively.
本文描述了一种基于适体/金纳米粒子的赭曲霉毒素 A（OTA）检测方法。该方法基于使用在 5'端标记有羧基荧光素（FAM）的适体和作为荧光猝灭剂的金纳米粒子（AuNPs）。当系统中不存在 OTA 时，荧光标记的适体被吸附在 AuNPs 表面。荧光标记的 OTA 适体产生的荧光信号被 AuNPs 的荧光共振能量转移效应猝灭。当系统中存在 OTA 时，荧光标记的适体与 OTA 结合形成折叠结构，能够抵抗 AuNPs 的吸附。因此，可以保留荧光信号。该传感平台的检测限为 5 nM，线性检测范围为 10-1000 nM（R = 0.994）。该方法通过在添加生姜粉样品中定量 OTA 进行了验证，并且发现样品基质不会产生干扰。回收率和相对标准偏差分别在 89.0%至 117.8%和 1.9%至 6.3%之间变化。
