1. Sensitive electrochemical immunoassay of carcinoembryonic antigen with signal dual-amplification using glucose oxidase and an artificial catalase.
- Author
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Tang J, Tang D, Li Q, Su B, Qiu B, and Chen G
- Subjects
- Animals, Biomarkers analysis, Biomarkers blood, Biosensing Techniques standards, Buffers, Carcinoembryonic Antigen blood, Electrochemistry standards, Ferrocyanides chemistry, Glucose chemistry, Gold chemistry, Graphite chemistry, Humans, Hydrogen-Ion Concentration, Immunoassay standards, Nanoparticles chemistry, Phosphates chemistry, Reference Standards, Reproducibility of Results, Silver chemistry, Biomimetic Materials chemistry, Biosensing Techniques methods, Carcinoembryonic Antigen analysis, Catalase, Electrochemistry methods, Glucose Oxidase metabolism, Immunoassay methods
- Abstract
A new dual-amplification strategy of electrochemical signal based on the catalytic recycling of the product was developed for the antigen-antibody interaction by glucose oxidase (GOD)- conjugated gold-silver hollow microspheres (AuAgHSs) coupled with an artificial catalase, Prussian blue nanoparticles (PB), on a graphene-based immunosensing platform. The first signal amplification introduced in this study was based on the labeled GOD on the AuAgHSs toward the catalytic oxidation of glucose. The generated H(2)O(2) was catalytically reduced by the immobilized PB on the graphene nanosheets with the second amplification. With a sandwich-type immunoassay format, carcinoembryonic antigen (CEA) was monitored as a model analyte by using the synthesized AuAgHSs as labels in pH 6.0 phosphate buffer containing 10mM glucose. Under optimal conditions, the electrochemical immunosensor exhibited a wide dynamic range of 0.005-50 ng mL(-1) with a low detection limit (LOD) of 1.0 pg mL(-1) CEA (at 3σ). Both the intra- and inter-assay coefficients of variation (CVs) were lower than 10%. The specificity and stability of the immunosensor were acceptable. In addition, the assay was evaluated for clinical serum specimens, and received a good correlation with those obtained by the referenced electrochemiluminescent (ECL)., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2011
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