title: Reusable split-aptamer-based biosensor for rapid detection of cocaine in serum by using an all-fiber evanescent wave optical biosensing platform.
abstract: 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.
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Yunfei
authors: Y
authors: Tang
authors: School of Environment and Natural Resources, Renmin University of China, Beijing 100872, China.
authors: Feng
authors: F
authors: Long
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Chunmei
authors: C
authors: Gu
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Cheng
authors: C
authors: Wang
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Shitong
authors: S
authors: Han
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: hemiao@mail.tsinghua.edu.cn.
authors: Miao
authors: M
authors: He
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques; D003042:Cocaine / Q000097:blood*; D006801:Humans; D055100:Optical Fibers
chemical_list: D052157:Aptamers, Nucleotide; D003042:Cocaine
keywords: Aptasensor; Cocaine; Evanescent wave; Fluorescence quenching; Structure switching