核酸适体传感法检测中药材中黄曲霉毒素B1

摘要

以自组装方法,构建了金纳米粒子/核酸适体/CdTe量子点复合物荧光传感体系,金纳米粒子使复合物中量子点荧光猝灭.样品溶液中存在黄曲霉毒素B1(AFB1)时,复合物中核酸适体选择性地与AFB1结合,并释放出量子点,使体系的荧光得到恢复,其荧光强度随加入样品中AFB1的量增大而增大.AFB1浓度在0.005~2.00 ng/mL范围与体系荧光强度恢复呈良好线性关系,检测限为1.2 pg/mL.该法用于连翘、山楂和甘草等中药材中痕量AFB1测定,取得了满意结果.%The nanocomposites of Au nanoparticles/aptamers/quantum dots were constructed by self-assembly. Fluorescence of CdTe quantum dots can be quenched by Au nanoparticles in the nanocomposites. The fluorescence of the system can recover when aflatoxin B1 (AFB1) is added to the assay solution,specific interactions between AFB1 and the aptamer cause release of the quantum dots. A linear fluorescence signal response to AFB1 concentration is obtained over a wide AFB1 con-centration range of 0.005-2.00 ng/mL with a detection limit of 1.2 pg/mL. The proposed method has been employed in the determination of trace AFB1 in forsythia suspense, hawthorn and radix liquiritiae successfully.