Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2028711 | Steroids | 2009 | 6 Pages |
Abstract
For the quantitative evaluation of low levels of an estriol metabolite of estriol (estriol-16-glucuronide (E3-16G)) in liquid media, we developed a simple and highly sensitive immunoassay using a surface plasmon resonance (SPR) biosensor which did not require any time-consuming sample pretreatment steps. E3-16G was conjugated to ovalbumin (OVA) through an oligoethylene glycol (OEG) linker to form protein conjugates (E3-16G-OEG-OVA), which were then immobilized on a carboxymethyl dextran-coated sensor chip via amine coupling to develop inhibition immunoassays. A limit of detection (LOD) of 76Â pg/mL was achieved using a rabbit anti-sheep primary antibody as a binding agent. The detection limit was further improved by using synthesized gold colloids (15Â nm) as high mass labels conjugated to the primary antibody. In this Au nanoparticle-enhanced assay, the concentration of E3-16G in aqueous samples could be determined in 7.5Â min at a level as low as 14Â pg/mL. In addition, the high stability of the E3-16G-OEG-OVA surface gave no obvious drop in antibody-binding capability after more than 1000 binding/regeneration cycles which significantly lowered the research cost.
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Authors
Xiuqian Jiang, Mark Waterland, Len Blackwell, Yinqiu Wu, Krishanthi P. Jayasundera, Ashton Partridge,