Improved functionality of antibody-colloidal gold conjugates with the aid of lipoamide-grafted N-[tris(hydroxymethyl)methyl]acrylamide polymers

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Researchers

Research units

  • VTT Technical Research Centre of Finland

Abstract

Colloidal gold has been used as a label in sandwich assays for human IgG, in which intercalating N-[tris(hydroxymethyl)methyl]acrylamide (pTHMMAA) polymers have been employed to stabilise the particles coated with antibody fragments. A direct absorbance reading of the particles could be obtained from sandwich assays on polystyrene, and a strongly amplified response was observed in similar assays based on Surface Plasmon Resonance (SPR): for h-IgG, detection limits below 100 pg/mL could be achieved. Three different polymer lengths and two different particles sizes were compared in sandwich assays performed on polystyrene and gold. The resulting binding curves fitted well to the Langmuir-Freundlich isotherm and the binding constants were in good agreement with the values found in earlier studies. The amplification afforded by the nanoparticles was strongly dependent on the antigen concentration, on the type of polymer and on the particle size. Compared to the direct response of the antigen, amplification factors larger than 100 could be achieved. The study proves that the polymers give stabilised particles, which can be used in highly sensitive sandwich assays. (C) 2010 Elsevier Inc. All rights reserved.

Details

Original languageEnglish
Pages (from-to)1-8
Number of pages8
JournalJournal of Colloid and Interface Science
Volume348
Issue number1
Publication statusPublished - 1 Aug 2010
MoE publication typeA1 Journal article-refereed

    Research areas

  • Colloidal gold, Antibody Fab'-fragment, Immobilisation, Stability, Surface Plasmon Resonance, Sandwich immunoassay, SURFACE-PLASMON RESONANCE, PROSTATE-SPECIFIC ANTIGEN, SITE-DIRECTED IMMOBILIZATION, ALPHA-LIPOIC ACID, NANOPARTICLES, FRAGMENTS, NUCLEATION, MONOLAYERS, DISULFIDE, BIOSENSOR

ID: 4464216