期刊
MICROCHIMICA ACTA
卷 182, 期 1-2, 页码 361-367出版社
SPRINGER WIEN
DOI: 10.1007/s00604-014-1333-3
关键词
Cocaine; Supramolecular aptamer; Rolling circle amplification; Multiplex binding system; Differential pulse voltammetry
资金
- National Natural Science Foundation of China [21075141, 81101638]
- Science and Technology Plan Project of Yuzhong District of Chongqing [20120212]
- Natural Science Foundation Project of CQ [CSTC2013jjB10019]
We report on a novel strategy for the electrochemical detection of cocaine. It is based on the use of a supramolecular aptamer, rolling circle amplification (RCA), and multiplex binding of a biotin-strepavidin system. The aptamer fragments were assembled to a supramolecular aptamer which, in the presence of cocaine, conjugates to streptavidin for anchoring of biotinylated circular DNA. This initiates RCA and enables sensitive electrochemical-enzymatic readout. A significant signal amplification was obtained by using streptavidin linked to alkaline phosphatase that binds to the remaining biotinylated detection probes and catalyzes the hydrolysis of the synthetic enzyme substrate alpha-naphthylphosphate. This dual amplification strategy tremendously increases the detection limit of the aptasensor. Under optimal conditions and using differential pulse voltammetry, cocaine can be detected in the concentration range between 2 and 500 nM with a detection limit as low as 1.3 nM (at S/N = 3). The method is specific and acceptably reproducible. It was successfully applied to the detection of cocaine in (spiked) urine samples. The data were in good agreement with those obtained by the GC-MS reference method.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据