title: An ATMND/SGI based label-free and fluorescence ratiometric aptasensor for rapid and highly sensitive detection of cocaine in biofluids.
abstract: A label-free ratiometric fluorescence aptasensor has been developed for the rapid and sensitive detection of cocaine in complex biofluids. The fluorescent aptasensor is composed of a non-labeled GC-38 cocaine aptamer which serves as a basic sensing unit and two fluorophores, 2-amino-5,6,7-trimethyl-1,8-naphthyridine (ATMND) and SYBR Green I (SGI) which serves as a signal reporter and a build-in reference, respectively. The detection principle is based on a specific cocaine mediated ATMND displacement reaction and the corresponding change in the fluorescence ratio of ATMND to SGI. Due to the high affinity of the non-labeled aptamer, the good precision originated from the ratiometric method, and the good fluorescence quantum yield of the fluorophore, the aptasensor shows good analytical performance with respect to cocaine detection. Under optimal conditions, the aptasensor shows a linear range of 0.10-10μM and a low limit of detection of 56nM, with a fast response of 20s. The low limit of detection is comparable to most of the fluorescent aptasensors with signal amplification strategies and much lower than all of the unamplified cocaine aptasensors. Practical sample analysis in a series of complex biofluids, including urine, saliva and serum, also indicates the good precision, stability, and high sensitivity of the aptasensor, which may have great potential for the point-of-care screening of cocaine in complex biofluids.
authors: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors: Jiamian
authors: J
authors: Wang
authors: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors: Jie
authors: J
authors: Song
authors: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors: Xiuyun
authors: X
authors: Wang
authors: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China. Electronic address: wushuo@dlut.edu.cn.
authors: Shuo
authors: S
authors: Wu
authors: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors: Yanqiu
authors: Y
authors: Zhao
authors: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors: Pinchen
authors: P
authors: Luo
authors: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors: Changgong
authors: C
authors: Meng
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D052160:Benzothiazoles; D003042:Cocaine / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000652:urine; D003959:Diamines; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D009287:Naphthyridines / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry*; D011804:Quinolines; D012463:Saliva / Q000737:chemistry
chemical_list: C528376:2-amino-5,6,7-trimethyl-1,8-naphthyridine; D052157:Aptamers, Nucleotide; D052160:Benzothiazoles; D003959:Diamines; D005456:Fluorescent Dyes; D009287:Naphthyridines; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I; D003042:Cocaine
keywords: Aptasensor; Biofluids; Cocaine; Label-free; Ratiometric