title: Layer-by-layer multienzyme assembly for highly sensitive electrochemical immunoassay based on tyramine signal amplification strategy.
abstract: A new sandwich-type electrochemical immunosensor based on nanosilver-doped bovine serum albumin microspheres (Ag@BSA) with a high ratio of horseradish peroxidase (HRP) and detection antibody was developed for quantitative monitoring of biomarkers (carcinoembryonic antigen, CEA, used in this case) by coupling enzymatic biocatalytic precipitation with tyramine signal amplification strategy on capture antibody-modified glassy carbon electrode. Two immunosensing protocols (with and without tyramine signal amplification) were also investigated for the detection of CEA and improved analytical features were acquired with tyramine signal amplification strategy. With the labeling method, the performance and factors influencing the electrochemical immunoassay were studied and evaluated in detail. Under the optimal conditions, the electrochemical immunosensor exhibited a wide dynamic range of 0.005-80 ng mL(-1) toward CEA standards with a low detection limit of 5.0 pg mL(-1). Intra- and inter-assay coefficients of variation were below 11%. No significant differences at the 0.05 significance level were encountered in the analysis of 6 clinical serum specimens and 6 spiked new-born cattle serum samples between the electrochemical immunoassay and the commercialized electrochemiluminescent immunoassay method for the detection of CEA.
authors.affiliation: Ministry of Education & Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China; Modern Biochemistry Center, Guangdong Ocean University, Zhanjiang 524088, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Ministry of Education & Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
authors.forename: Juan
authors.initials: J
authors.lastname: Tang
authors.affiliation: Ministry of Education & Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
authors.affiliation: Ministry of Education & Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China. Electronic address: dianping.tang@fzu.edu.cn.
authors.forename: Dianping
authors.initials: D
authors.lastname: Tang
mesh_terms: D000818:Animals; D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation; D002272:Carcinoembryonic Antigen / Q000032:analysis / Q000097:blood*; D002417:Cattle; D055664:Electrochemical Techniques / Q000295:instrumentation; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008958:Models, Molecular; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D014439:Tyramine / Q000737:chemistry*
chemical_list: D055910:Antibodies, Immobilized; D002272:Carcinoembryonic Antigen; D012710:Serum Albumin, Bovine; D012834:Silver; D014439:Tyramine
keywords: Carcinoembryonic antigen; Electrochemical immunosensor; Multienzyme assembly; Nanosilver-doped bovine serum albumin microspheres; Tyramine signal amplification