title: A doubly amplified electrochemical immunoassay for carcinoembryonic antigen.
abstract: An ultrasensitive electrochemical immunoassay (EIA) for the detection of carcinoembryonic antigen (CEA) is described in this report. The assay involves utilizing enzyme-catalyzed deposition of a redox polymer and electrocatalytic oxidation of ascorbic acid (AA) by the deposited redox polymer, a dual-amplification scheme to enhance analytical signals. Briefly, CEA capturing antibody and redox polymer anchoring agent were covalently immobilized on a gold electrode. After incubating with CEA, the electrode was treated in detection antibody-glucose oxidase conjugate solution. Thereafter, it was dipped into the redox polymer solution. Upon the addition of glucose, the redox polymer was enzymatically reduced and deposited on the electrode surface. The deposited redox polymer exhibits excellent electrocatalytic activity towards the oxidation of AA. Consequently, CEA could be quantified amperometrically. This electrochemical immunoassay combines the specificity of the immunological reaction with the sensitivity of the doubly amplified electrochemical detection.
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, 138669, Singapore.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Gao
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Boon Ping
authors.initials: BP
authors.lastname: Ting
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D017076:Computer-Aided Design; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002272:Carcinoembryonic Antigen