Tang Yunfei, Long Feng, Gu Chunmei, Wang Cheng, Han Shitong, He Miao
State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
School of Environment and Natural Resources, Renmin University of China, Beijing 100872, China.
Anal Chim Acta. 2016 Aug 24;933:182-8. doi: 10.1016/j.aca.2016.05.021. Epub 2016 May 24.
A rapid, facile, and sensitive assay of cocaine in biological fluids is important to prevent illegal abuse of drugs. A two-step structure-switching aptasensor has been developed for cocaine detection based on evanescent wave optical biosensing platform. In the proposed biosensing platform, two tailored aptamer probes were used to construct the molecular structure switching. In the existence of cocaine, two fragments of cocaine aptamer formed a three-way junction quickly, and the fluorophore group of one fragment was effectively quenched by the quencher group of the other one. The tail of the three-way junction hybridized with the cDNA sequences immobilized on the optical fiber biosensor. Fluorescence was excited by evanescent wave, and the fluorescence signal was proportional to cocaine concentration. Cocaine was detected in 450 s (300 s for incubation and 150 s for detection and regeneration) with a limit of detection (LOD) of 165.2 nM. The proposed aptasensor was evaluated in human serum samples, and it exhibited good recovery, precision, and accuracy without complicated sample pretreatments.
对生物体液中的可卡因进行快速、简便且灵敏的检测对于防止非法药物滥用至关重要。基于倏逝波光学生物传感平台，开发了一种用于可卡因检测的两步结构转换适体传感器。在所提出的生物传感平台中，使用两个定制的适体探针构建分子结构转换。在可卡因存在的情况下，可卡因适体的两个片段迅速形成一个三向连接，一个片段的荧光团被另一个片段的猝灭团有效猝灭。三向连接的尾部与固定在光纤生物传感器上的cDNA序列杂交。通过倏逝波激发荧光，荧光信号与可卡因浓度成正比。在450秒内（300秒用于孵育，150秒用于检测和再生）检测到可卡因，检测限（LOD）为165.2 nM。所提出的适体传感器在人血清样本中进行了评估，无需复杂的样品预处理，具有良好的回收率、精密度和准确性。
