基于金属有机框架的荧光适配体传感器检测红酒中黄曲霉毒素B1

A Metal-organic Framework-based Fluorescent Aptasensor for Determination of Aflatoxin B1 in Red Wine

摘要:

该文利用金属有机框架（Metal-organic Framework，MOF）材料和荧光标记的核酸适配体构建一种基于光诱导电子转移的荧光适配体传感器用于黄曲霉毒素B1（Aflatoxin B1，AFB1）的检测。MOF材料为氨基功能化的奥斯陆大学66（Amino-functionalized University of Oslo 66，UiO-66-NH2），标记有四甲基罗丹明（Tetramethylrhodamine，TAMRA）荧光团的核酸适配体（TAMRA-aptamer）通过π-π堆积作用吸附于UiO-66-NH2表面，由于光诱导电子转移使TAMRA-aptamer的荧光猝灭。加入目标物AFB1后，核酸适配体与AFB1特异性识别并结合，使核酸适配体从单链结构转变为稳定的内环结构。由于内环结构与UiO-66-NH2之间的结合能力较弱，光诱导电子转移被阻断，TAMRA-aptamer荧光恢复。该荧光适配体传感器用于AFB1检测，在1.00~100.00 ng/mL范围内荧光信号强度与AFB1浓度具有良好的线性相关性，相关系数的平方（R2）为0.994，检测限为0.50 ng/mL。该方法用于红酒中AFB1的测定，样品添加回收率为90.00%~101.00%。该方法操作简便、成本低、选择性好、灵敏度高，可用于红酒中AFB1的快速检测。

Abstract:

A fluorescent aptasensor was constructed based on photoinduced electron transfer using an amino-functionalized metal-organic framework (MOF) from the University of Oslo 66 (UiO-66-NH2) and fluorescently labeled aptamers for the determination of aflatoxin B1 (AFB1). Tetramethylrhodamine-labeled (TAMRA-labeled) aptamers (TAMRA-aptamer) were absorbed onto the surface of the UiO-66-NH2 via π-π stacking and the fluorescence of the TAMRA-aptamer was quenched due to the photoinduced electron transfer. The conformation of TAMRA-aptamers, which specifically recognize and bind to AFB1, changed from a single chain to a stable internal loop, and the hindrance of photoinduced electron transfer due to the weak binding ability between the internal loop structure and UiO-66-NH2 led again to fluorescence of the TAMRA-aptamers. The fluorescent aptasensor is thus considered suitable for AFB1 detection to as low as 0.50 ng/mL. The intensity was proportional to AFB1 concentration in the range between 1.00 and 100.00 ng/mL, and the square of the correlation coefficient (R2) was 0.994. The recovery for the detection of AFB1 in red wine was 90.00~101.00%. The developed method is simple, inexpensive, reasonably selective, and highly sensitive and can be used for the rapid determination of AFB1 in red wine.