title: Amplified detection of cocaine based on strand-displacement polymerization and fluorescence resonance energy transfer.
abstract: Cocaine is one of the most abused drugs in the United States and is potentially dangerous when consumed in excess. Its detection is thus important in many areas in the fight against drug trafficking. We have developed an amplified detection method for cocaine based on a strand-displacement polymerization reaction using aptamer recognition. The system mainly consists of a hairpin probe with Cy5 labeled on its 3' end, a primer with FAM labeled on its 5' end, and polymerase. The aptamer sequence is integrated into the 5'-section of the hairpin probe. The primer is designed complementary to the 3' end of the hairpin probe, which is also part of the hairpin stem region. The cocaine induced reaction cycle generates product for detection and thus for signal amplification. The detection limit of this method is 200 nM in about 16 min and the specificity of this approach is excellent. We believe that this strategy will be useful for the development of analytical schemes for a variety of aptamers for small molecules, metal ions, and proteins. This simple scheme employing the strand-displacement polymerization reaction may find wide application in forensic analysis, environmental monitoring, and clinical diagnostics.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Huang
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhu
authors.forename: Guizhi
authors.initials: G
authors.lastname: Zhu
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Yang
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D003042:Cocaine / Q000032:analysis* / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D058105:Polymerization; D052156:SELEX Aptamer Technique; D012680:Sensitivity and Specificity
chemical_list: D003042:Cocaine