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A dual-signal readout enzyme-free immunosensor based on hybridization chain reaction-assisted formation of copper nanoparticles for the detection of microcystin-LR

文献类型: 外文期刊

作者: He, Zuyu 1 ; Cai, Yue 1 ; Yang, Ziming 2 ; Li, Puwang 2 ; Lei, Hongtao 3 ; Liu, Weipeng 1 ; Liu, Yingju 1 ;

作者机构: 1.South China Agr Univ, Coll Mat & Energy, Guangzhou 510642, Guangdong, Peoples R China

2.Chinese Acad Trop Agr Sci, Agr Prod Proc Res Inst, Zhanjiang 524001, Peoples R China

3.South China Agr Univ, Coll Food Sci, Guangdong Prov Key Lab Food Qual & Safety, Guangzhou 510642, Guangdong, Peoples R China

关键词: Immunoassay; Dual-signal readout; Hybridization chain reaction; Microcystin-LR

期刊名称:BIOSENSORS & BIOELECTRONICS ( 影响因子:10.618; 五年影响因子:9.323 )

ISSN: 0956-5663

年卷期: 2019 年 126 卷

页码:

收录情况: SCI

摘要: Enzyme-based electrochemical biosensors are widely used in immunoassays, but the intrinsic disadvantages of enzymes including instability or sensitivity to temperature and pH should be considered. Herein, an enzyme-free and dual-signal readout immunoassay was established to detect microcystin-LR (MC-LR) sensitively and selectively. Firstly, the microplate was modified with gold nanoparticles-decorated-carbon nanotubes (AuNP-CNT) to immobilize sufficient antigens by the high surface area of CNT and high affinity of AuNP. Then, silver nanoparticles were decorated on gold nanorods to form corn-like AgNP/AuNR composite and then capture secondary antibody and initiator DNA strand. After hybridization chain reaction, long double helix DNA strands can be formed on AgNP/AuNR to germinate copper nanoparticles. A dual-signal readout from the current responses of both silver and copper ions was obtained by using differential pulse stripping voltammetry with the aid of acid treatment, By using a competitive immunoreaction, MC-LR can be detected in a linear range from 0.005 mu g/L to 20 mu g/L with a lower detection limit of 2.8 mu g/L. The reproducibility, stability and specificity were all acceptable, indicating its promising application in environment monitoring and sensitive electrochemical detection for other analytes.

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