Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10375066 | Colloids and Surfaces B: Biointerfaces | 2005 | 6 Pages |
Abstract
The immobilization of anti-IgG on Au-colloid modified gold electrodes has been investigated. A cleaned gold electrode was first immersed in a mercaptoethylamine (AET) solution, and then gold nanoparticles were chemisorbed onto the thiol groups of the mercaptoethylamine. Finally, anti-IgG was adsorbed onto the surface of the gold nanoparticles. Potentiometric immunosensor, cyclic voltammetry, and electrochemical impedance techniques were used to investigate the immobilization of anti-IgG on Au colloids. In the impedance spectroscopic study, an obvious difference of the electron transfer resistance between the Au-colloid modified electrode and the bare gold electrode was observed. The cyclic voltammogram tends to be more irreversible with increased anti-IgG concentration. Using the potentiometric immunosensor, the proposed technique is based on that the specific agglutination of antibody-coated gold nanoparticles, averaging 16 nm in diameter, in the presence of the corresponding antigen causes a potential change that is monitored by a potentiometry. It is found that the developed immunoagglutination assay system is sensitive to the concentration of IgG antigen as low as 12 ng mLâ1. Experimental results showed that the developed technique is in satisfactory agreement with the ELISA method, and that gold nanoparticles can be used as a biocompatible matrix for antibody or antigen immobilization.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Yingzi Fu, Ruo Yuan, Dianping Tang, Yaqin Chai, Lan Xu,