Nanostar Clustering Improves the Sensitivity of Plasmonic Assays

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• 作者：Yong Il Park ; Hyungsoon Im ; Ralph Weissleder ; Hakho Lee
• 刊名：Bioconjugate Chemistry
• 出版年：2015
• 出版时间：August 19, 2015
• 年：2015
• 卷：26
• 期：8
• 页码：1470-1474
• 全文大小：307K
• ISSN：1520-4812

文摘

Star-shaped Au nanoparticles (Au nanostars, AuNS) have been developed to improve the plasmonic sensitivity, but their application has largely been limited to single-particle probes. We herein describe a AuNS clustering assay based on nanoscale self-assembly of multiple AuNS and which further increases detection sensitivity. We show that each cluster contains multiple nanogaps to concentrate electric fields, thereby amplifying the signal via plasmon coupling. Numerical simulation indicated that AuNS clusters assume up to 460-fold higher field density than Au nanosphere clusters of similar mass. The results were validated in model assays of protein biomarker detection. The AuNS clustering assay showed higher sensitivity than Au nanosphere. Minimizing the size of affinity ligand was found important to tightly confine electric fields and improve the sensitivity. The resulting assay is simple and fast and can be readily applied to point-of-care molecular detection schemes.