Article ID Journal Published Year Pages File Type
742109 Sensors and Actuators B: Chemical 2013 7 Pages PDF
Abstract

In the paper, a simple and sensitive sandwich-type electrochemiluminescence (ECL) immunosensor was proposed for the detection of cancer antigen 125 (CA 125) on a nanoporous gold (NPG) modified glassy carbon electrode (GCE). The NPG was easily prepared by a selective dissolution of silver from silver/gold alloy in nitric acid. The fabrication of Ru(bpy)32+-gold nanoparticles (Ru-AuNPs) aggregates was owing to the electrostatic interactions between citrate-capped AuNPs and Ru in aqueous medium. The Ru-AuNPs composite assembled with poly(diallyldimethylammonium chloride) functionalized graphene nanosheets (GR) (Ru-AuNPs/GR) was used as ECL labels, which has large surface area, good biocompatibility and electronic conductivity. The ECL intensity observed by the application of as-prepared Ru-AuNPs/GR composites was enhanced 6-fold compared to those of Ru-AuNPs. The primary antibody of CA 125 (Ab1) was first immobilized on the NPG modified electrode, then the antigen and the secondary antibody (Ab2) were conjugated to form a sandwich-type immunocomplex through the specific interaction. The proposed ECL immunosensor provided a wide linear response range over 0.01–100 U mL−1 with a detection limit of 0.005 U mL−1. The ECL immunosensor showed high sensitivity, good reproducibility, satisfied regeneration and selectivity, and may exhibit an attractive approach for other analyte determination.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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