Aptamer-Modified Gold Nanoparticles for Colorimetric Determination of Platelet-Derived Growth Factors and Their Receptors
Journal
Analytical Chemistry
Journal Volume
77
Journal Issue
17
Pages
5735-5741
Date Issued
2005
Date
2005
Author(s)
Abstract
We have developed a highly specific sensing system for platelet-derived growth factors (PDGFs) and platelet-derived growth factor receptors (PDGFR) that uses gold nanoparticles (GNPs). We synthesized GNPs modified with an aptamer (Apt-GNPs) that is specific to PDGFs and used them to detect PDGFs by monitoring the changes in the color and extinction of the Apt-GNPs that occur as a result of aggregation. The color of the Apt-GNPs changes from red to purple at low concentrations (<400 nM), but changes only slightly at higher concentrations (> 400 nM). We found that the sensitivity of the Apt-GNPs for the three PDGFs is highly salt-dependent, with an optimum condition of 200 mM NaCl. We obtained biphasic curves when plotting of the ratios of the extinction coefficients of the Apt-GNPs at 650 and 530 nm against the concentrations of PDGF-AA at various concentrations of Apt-GNPs. The linear ranges of the increases and decreases in this extinction ratio are 2.5-10 and 10-20 nM, respectively, for 0.42 nM Apt-GNPs and 25-75 and 75-200 nM, respectively, for 8.4 nM Apt-GNPs. When using 8.4 nM Apt-GNPs, the corresponding linear ranges of the increases and decreases in this extinction ratio are 15-100 and 100-400 nM, respectively, for PDGF-AB and 35-150 and 150-400 nM, respectively, for PDGF-BB. In addition, we have developed a homogeneous assay to detect the PDGF receptor-β (PDGFR-β) at concentrations as low as 3.2 nM, on the basis of the competition between the Apt-GNPs and PDGFR-β for PDGF-BB. The results we present in this paper imply that there are practical applications of Apt-GNPs in protein analysis and cancer diagnosis. ? 2005 American Chemical Society.
SDGs
Other Subjects
Aptamers; Colorimetric determination; Gold nanoparticles; Platelet-derived growth factor receptors (PDGFR); Agglomeration; Bioassay; Colorimetric analysis; Concentration (process); Gold; Proteins; Sodium chloride; Synthesis (chemical); Nanostructured materials; aptamer; gold; nanoparticle; platelet derived growth factor; platelet derived growth factor AA; platelet derived growth factor BB; platelet derived growth factor beta receptor; platelet derived growth factor receptor; sodium chloride; article; binding competition; biosensor; calibration; cancer diagnosis; colorimetry; electrophoretic mobility; pH; protein aggregation; protein analysis; protein secondary structure; transmission electron microscopy; ultraviolet spectrophotometry; Aptamers, Nucleotide; Base Sequence; Colorimetry; Gold; Humans; Microscopy, Electron, Transmission; Molecular Structure; Nanoparticles; Platelet-Derived Growth Factor; Receptors, Platelet-Derived Growth Factor
Type
journal article
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