Department of Physics, Duke University , Durham, North Carolina 27708, United States.
Nano Lett. 2014;14(4):2099-104. doi: 10.1021/nl5003069. Epub 2014 Mar 20.
DNA origami is a novel self-assembly technique allowing one to form various two-dimensional shapes and position matter with nanometer accuracy. We use DNA origami templates to engineer surface-enhanced Raman scattering substrates. Specifically, gold nanoparticles were selectively placed on the corners of rectangular origami and subsequently enlarged via solution-based metal deposition. The resulting assemblies exhibit "hot spots" of enhanced electromagnetic field between the nanoparticles. We observed a significant Raman signal enhancement from molecules covalently attached to the assemblies, as compared to control nanoparticle samples that lack interparticle hot spots. Furthermore, Raman molecules are used to map out the hot spots' distribution, as they are burned when experiencing a threshold electric field. Our method opens up the prospects of using DNA origami to rationally engineer and assemble plasmonic structures for molecular spectroscopy.
DNA 折纸术是一种新颖的自组装技术，能够形成各种二维形状，并以纳米精度定位物质。我们使用 DNA 折纸模板来设计表面增强拉曼散射基底。具体来说，将金纳米粒子选择性地放置在矩形折纸的角上，然后通过基于溶液的金属沉积将其放大。所得组装体在纳米粒子之间表现出增强电磁场的“热点”。与缺乏粒子间热点的对照纳米粒子样品相比，我们观察到共价附着在组装体上的分子的拉曼信号显著增强。此外，拉曼分子被用来绘制热点的分布，因为当它们经历阈值电场时会被烧掉。我们的方法为使用 DNA 折纸术合理地设计和组装等离子体结构以用于分子光谱学开辟了前景。
