文献类型：期刊文献

英文题名：Nanogold-Functionalized DNAzyme Concatamers with Redox-Active Intercalators for Quadruple Signal Amplification of Electrochemical Immunoassay

作者：Zhou, Jun[1,2,3];Lai, Wenqiang[1,2];Zhuang, Junyang[1,2];Tang, Juan[1,2];Tang, Dianping[1,2]

机构：[1]Fuzhou Univ, Key Lab Anal & Detect Food Safety, Fuzhou 350108, Peoples R China;[2]Fuzhou Univ, Dept Chem, Minist Educ China, Fuzhou 350108, Peoples R China;[3]Guangdong Ocean Univ, Modern Biochem Ctr, Zhanjiang 524088, Guangdong, Peoples R China

年份：2013

卷号：5

期号：7

起止页码：2773

外文期刊名：ACS APPLIED MATERIALS & INTERFACES

收录：SCI-EXPANDED(收录号：WOS:000317549100064)、、EI(收录号：20131616216076)、Scopus(收录号：2-s2.0-84876133445)、WOS

基金：Support by the "973" National Basic Research Program of China (2010CB732403), the Research Fund for the National Science Foundation of Fujian Province (2011J06003), the Doctoral Program of Higher Education of China (20103514120003), the National Natural Science Foundation of China (21075019 and 41176079), and the Program for Changjiang Scholars and Innovative Research Team in University (IRT1116) is gratefully acknowledged.

语种：英文

外文关键词：electrochemical immunoassay; gold nanoparticles; DNAzyme concatamers; quadruple single amplification

外文摘要：A novel and in situ amplified immunoassay strategy with quadruple signal amplification was designed for highly efficient electrochemical detection of low-abundance proteins (carcinoembryonic antigen, CEA, as a model) by using nanogold-functionalized DNAzyme concatamers with redox-active intercalators. To construct such an in situ amplification system, streptavidin-labeled gold nanoparticles (AuNP-SA) were initially used for the labelling of initiator strands (So) and detection antibody (mAb(2)) with a large ratio (mAb(2)-AuNP-S-0), and then two auxiliary DNA strands S-1 and S-2 were designed for in situ propagation of DNAzyme concatamers with the hemin/G-quadruplex format. The quadruple signal amplification was implemented by using the avidinbiotin chemistry, nanogold labels, DNA concatamers, and DNAzymes. In the presence of target CEA, the sandwiched immunocomplex was formed between the immobilized primary antibodies on the electrode and the conjugated detection antibodies on the mAb(2)-AuNP-S-0. The carried So initiator strands could progress a chain reaction of hybridization events between alternating S-1/S-2 DNA strands to form a nicked double-helix. Upon addition of hemin, the hemin-binding aptamers could be bound to form the hemin/Gquadruplex-based DNAzymes. The formed double-helix DNA polymers could cause the intercalation of numerous electroactive methylene blue molecules. During the electrochemical measurement, the formed DNAzymes could catalyze the reduction of H2O2 in the solution to amplify the electrochemical signal of the intercalated methylene blue. Under optimal conditions, the electrochemical immunoassay exhibited a wide dynamic range of 1.0 fg mL(-1) to 20 ng mL(-1) toward CEA standards with a low detection limit of 0.5 fg Intra-assay and inter-assay coefficients of variation (CV) were less than 8.5% and 11.5%, respectively. No significant differences at the 0.05 significance level were encountered in the analysis of 14 clinical serum specimens between the developed immunoassay and commercialized electrochemiluminescent (ECL) method for detection of CEA.