A sensitive immunosensor using colloidal gold as electrochemical label.
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.
Chen
Zhao-Peng
ZP
State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
Peng
Zhao-Feng
ZF
Zhang
Peng
P
Jin
Xue-Fang
XF
Jiang
Jian-Hui
JH
Zhang
Xiao-Bing
XB
Shen
Guo-Li
GL
Yu
Ru-Qin
RQ