Gold Nanoparticle Labels and Heterogeneous Immunoassays: The Case for the Inverted Substrate
| Autor: | Colin C. Young, Alexis C. Crawford, Marc D. Porter |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Immunoassay
Detection limit Surface Properties Chemistry Extramural Metal Nanoparticles Nanoparticle 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Antigen capture 0104 chemical sciences Analytical Chemistry Diffusion Adsorption Chemical physics Immunoglobulin G Humans Gold 0210 nano-technology |
| Zdroj: | Analytical Chemistry. 90:8665-8672 |
| ISSN: | 1520-6882 0003-2700 |
| DOI: | 10.1021/acs.analchem.8b02011 |
| Popis: | This paper examines how the difference in the spatial orientation of the capture substrate influences the analytical sensitivity and limits of detection for immunoassays that use gold nanoparticle labels (AuNPs) and rely on diffusion in quiet solution in the antigen capture and labeling steps. Ideally, the accumulation of both reactants should follow a dependence governed by the rate in which diffusion delivers reactants to the capture surface. In other words, the accumulation of reactants should increase with the square root of the incubation time, i.e., t1/2. The work herein shows, however, that this expectation is only obeyed when the capture substrate is oriented to direct the gravity-induced sedimentation of the AuNP labels away from the substrate. Using an assay for human IgG, the results show that circumventing the sedimentation of the gold nanoparticle labels by substrate inversion enables the dependence of the labeling step on diffusion, reduces nonspecific label adsorption, and improves the esti... |
| Databáze: | OpenAIRE |
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