title: A sensitive immunosensor using colloidal gold as electrochemical label.
abstract: A sensitive immunosensor using colloidal gold as electrochemical label is described. In this method, the capture protein was first immobilized on a carbon paste electrode surface through passive adsorption to bind quantitatively with corresponding antigen and colloidal gold labeled antibody to perform a sandwich assay. To detect the amount of the colloidal gold captured on the electrode surface, the colloid was first oxidized electrochemically to produce AuCl(4)(-) ions which were adsorbed strongly on the electrode surface. Adsorptive voltammetry was then employed for the determination of the adsorbed AuCl(4)(-) ions. A linear relationship between reduction wave peak current and the antigen concentration (human IgG) from 10 to 500 ng/ml is obtained with a detection limit of 4.0 ng/ml.
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Zhao-Peng
authors.initials: ZP
authors.lastname: Chen
authors.forename: Zhao-Feng
authors.initials: ZF
authors.lastname: Peng
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Xue-Fang
authors.initials: XF
authors.lastname: Jin
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Jiang
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Zhang
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Shen
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu