title: Sensitive electrochemical immunoassay of carcinoembryonic antigen with signal dual-amplification using glucose oxidase and an artificial catalase.
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).
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, PR China.
authors.forename: Juan
authors.initials: J
authors.lastname: Tang
authors.forename: Dianping
authors.initials: D
authors.lastname: Tang
authors.forename: Qunfang
authors.initials: Q
authors.lastname: Li
authors.forename: Biling
authors.initials: B
authors.lastname: Su
authors.forename: Bin
authors.initials: B
authors.lastname: Qiu
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D040761:Biomimetic Materials / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods* / Q000592:standards; D002021:Buffers; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000097:blood; D002374:Catalase; D004563:Electrochemistry / Q000379:methods* / Q000592:standards; D005295:Ferrocyanides / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D005949:Glucose Oxidase / Q000378:metabolism*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay / Q000379:methods* / Q000592:standards; D053758:Nanoparticles / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D012015:Reference Standards; D015203:Reproducibility of Results; D012834:Silver / Q000737:chemistry
chemical_list: D015415:Biomarkers; D002021:Buffers; D002272:Carcinoembryonic Antigen; D005295:Ferrocyanides; D010710:Phosphates; D012834:Silver; D006046:Gold; D006108:Graphite; D005949:Glucose Oxidase; D002374:Catalase; D005947:Glucose; C000170:ferric ferrocyanide