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Nanogold-functionalized DNAzyme concatamers with redox-active intercalators for quadruple signal amplification of electrochemical immunoassay.
ACS Appl Mater Interfaces. 2013 Apr 10; 5(7):2773-81.AA

Abstract

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 (S0) and detection antibody (mAb2) with a large ratio (mAb2-AuNP-S0), and then two auxiliary DNA strands S1 and S2 were designed for in situ propagation of DNAzyme concatamers with the hemin/G-quadruplex format. The quadruple signal amplification was implemented by using the avidin-biotin 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 mAb2-AuNP-S0. The carried S0 initiator strands could progress a chain reaction of hybridization events between alternating S1/S2 DNA strands to form a nicked double-helix. Upon addition of hemin, the hemin-binding aptamers could be bound to form the hemin/G-quadruplex-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 mL(-1). 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.

Authors+Show Affiliations

Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & Ministry of Education of China), Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

23488856

Citation

Zhou, Jun, et al. "Nanogold-functionalized DNAzyme Concatamers With Redox-active Intercalators for Quadruple Signal Amplification of Electrochemical Immunoassay." ACS Applied Materials & Interfaces, vol. 5, no. 7, 2013, pp. 2773-81.
Zhou J, Lai W, Zhuang J, et al. Nanogold-functionalized DNAzyme concatamers with redox-active intercalators for quadruple signal amplification of electrochemical immunoassay. ACS Appl Mater Interfaces. 2013;5(7):2773-81.
Zhou, J., Lai, W., Zhuang, J., Tang, J., & Tang, D. (2013). Nanogold-functionalized DNAzyme concatamers with redox-active intercalators for quadruple signal amplification of electrochemical immunoassay. ACS Applied Materials & Interfaces, 5(7), 2773-81. https://doi.org/10.1021/am400652g
Zhou J, et al. Nanogold-functionalized DNAzyme Concatamers With Redox-active Intercalators for Quadruple Signal Amplification of Electrochemical Immunoassay. ACS Appl Mater Interfaces. 2013 Apr 10;5(7):2773-81. PubMed PMID: 23488856.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Nanogold-functionalized DNAzyme concatamers with redox-active intercalators for quadruple signal amplification of electrochemical immunoassay. AU - Zhou,Jun, AU - Lai,Wenqiang, AU - Zhuang,Junyang, AU - Tang,Juan, AU - Tang,Dianping, Y1 - 2013/03/29/ PY - 2013/3/16/entrez PY - 2013/3/16/pubmed PY - 2015/10/16/medline SP - 2773 EP - 81 JF - ACS applied materials & interfaces JO - ACS Appl Mater Interfaces VL - 5 IS - 7 N2 - 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 (S0) and detection antibody (mAb2) with a large ratio (mAb2-AuNP-S0), and then two auxiliary DNA strands S1 and S2 were designed for in situ propagation of DNAzyme concatamers with the hemin/G-quadruplex format. The quadruple signal amplification was implemented by using the avidin-biotin 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 mAb2-AuNP-S0. The carried S0 initiator strands could progress a chain reaction of hybridization events between alternating S1/S2 DNA strands to form a nicked double-helix. Upon addition of hemin, the hemin-binding aptamers could be bound to form the hemin/G-quadruplex-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 mL(-1). 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. SN - 1944-8252 UR - https://www.unboundmedicine.com/medline/citation/23488856/Nanogold_functionalized_DNAzyme_concatamers_with_redox_active_intercalators_for_quadruple_signal_amplification_of_electrochemical_immunoassay_ L2 - https://doi.org/10.1021/am400652g DB - PRIME DP - Unbound Medicine ER -