title: Simultaneous detection of four biomarkers with one sensing surface based on redox probe tagging strategy.
abstract: In this paper, a simple and sensitive amperometric immunosensor for simultaneous detection of four biomarkers by using distinguishable redox-probes as signal tags was proposed for the first time. In sandwich immunoassay format, four kinds of capture antibodies (C-Ab) were immobilized by gold nanoparticles (AuNPs) electro-deposited on the surface of glass carbon electrode (GCE); four kinds of detection antibodies (D-Ab) labeled with different redox probes (including anthraquinone 2-carboxylic acid (Aq), thionine (Thi), ferrocenecarboxylic acid (Fc) and tris(2,2'-bipyridine-4,4'-dicarboxylic acid) cobalt(III) (Co(bpy)3(3+))), were combined with 3,4,9,10-perylenetetracarboxylic acid (PTCA), poly(diallyldimethylammonium chloride) (PDDA) and AuNPs functionalized carbon nanotubes, and served as signal tracer. When four target antigens were present, differential pulse voltammetry (DPV) scan exhibited four well-resolved peaks, each peak indicated one antigen, and its intensity was quantitative correlational to the concentration of corresponding analyte. To verify the strategy, four biomarkers for diagnosis of colorectal carcinoma, including carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9 CA125, and CA242, were used as model analytes, the immunosensor exhibited high selectivity and sensitivity, and peak current displayed good linear relationship to logarithm concentration in the ranges from 0.016 to 15 ng mL(-1) for CEA; 0.008 to 10 ng mL(-1) for CA19-9; 0.012 to 12 ng mL(-1) for CA125; 0.010 to 10 ng mL(-1) for CA242, and low detection limits of 4.2, 2.8, 3.3 and 3.8 pg mL(-1), respectively.
authors.affiliation: The Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Southwest University, Chongqing 400715, China; College of Chemistry, Chongqing Normal University, Chongqing 400047, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhu
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhuo
mesh_terms: D000880:Anthraquinones / Q000737:chemistry; D000906:Antibodies / Q000032:analysis; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000032:analysis; D015415:Biomarkers / Q000032:analysis*; D018394:CA-125 Antigen / Q000032:analysis; D018395:CA-19-9 Antigen / Q000032:analysis; D002272:Carcinoembryonic Antigen / Q000032:analysis; D056831:Coordination Complexes / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D000075163:Metallocenes; D037742:Nanotubes, Carbon / Q000737:chemistry; D010084:Oxidation-Reduction; D010640:Phenothiazines / Q000737:chemistry
chemical_list: D000880:Anthraquinones; D000906:Antibodies; D015295:Antigens, Tumor-Associated, Carbohydrate; D015415:Biomarkers; C074601:CA 242 antigen; D018394:CA-125 Antigen; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen; D056831:Coordination Complexes; D005296:Ferrous Compounds; D000075163:Metallocenes; D037742:Nanotubes, Carbon; D010640:Phenothiazines; C498247:anthraquinone-2-carboxylic acid; C032949:ferrocenecarboxylic acid; C009469:thionine
keywords: 3,4,9,10-Perylenetetracarboxylic acid; Functionalized carbon nanotube; Gold nanoparticle; Redox probe; Sandwich amperometric immunosensor; Simultaneous multianalytes immunoassays