Aptamer-Modified Gold Nanoparticles for Colorimetric Determination of Platelet-Derived Growth Factors and Their Receptors

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• 作者：Chih-Ching Huang ; Yu-Fen Huang ; Zehui Cao ; Weihong Tan ; and Huan-Tsung Chang
• 刊名：Analytical Chemistry
• 出版年：2005
• 出版时间：September 1, 2005
• 年：2005
• 卷：77
• 期：17
• 页码：5735 - 5741
• 全文大小：314K
• 年卷期：v.77,no.17(September 1, 2005)
• ISSN：1520-6882

文摘

We have developed a highly specific sensing system forplatelet-derived growth factors (PDGFs) and platelet-derived growth factor receptors (PDGFR) that uses goldnanoparticles (GNPs). We synthesized GNPs modifiedwith an aptamer (Apt-GNPs) that is specific to PDGFs andused them to detect PDGFs by monitoring the changesin the color and extinction of the Apt-GNPs that occur asa result of aggregation. The color of the Apt-GNPs changesfrom red to purple at low concentrations (<400 nM), butchanges only slightly at higher concentrations (>400 nM).We found that the sensitivity of the Apt-GNPs for the threePDGFs is highly salt-dependent, with an optimum condition of 200 mM NaCl. We obtained biphasic curves whenplotting of the ratios of the extinction coefficients of theApt-GNPs at 650 and 530 nm against the concentrationsof PDGF-AA at various concentrations of Apt-GNPs. Thelinear ranges of the increases and decreases in thisextinction 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 nMApt-GNPs, the corresponding linear ranges of the increases and decreases in this extinction ratio are 15-100and 100-400 nM, respectively, for PDGF-AB and 35-150 and 150-400 nM, respectively, for PDGF-BB. Inaddition, we have developed a homogeneous assay todetect the PDGF receptor- (PDGFR-) at concentrationsas low as 3.2 nM, on the basis of the competition betweenthe Apt-GNPs and PDGFR- for PDGF-BB. The resultswe present in this paper imply that there are practicalapplications of Apt-GNPs in protein analysis and cancerdiagnosis.