Sebba David S, Mock Jack J, Smith David R, Labean Thomas H, Lazarides Anne A
Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA.
Nano Lett. 2008 Jul;8(7):1803-8. doi: 10.1021/nl080029h. Epub 2008 Jun 10.
Molecular control of plasmon coupling is investigated in sub-100 nm assemblies composed of 13 nm gold "satellite" particles tethered by reconfigurable DNA nanostructures to a 50 nm gold "core" particle. Reconfiguration of the DNA nanostructures from a compact to an extended state results in blue shifting of the assembly plasmon resonance, indicating reduced interparticle coupling and lengthening of the core-satellite tether. Scattering spectra of the core-satellite assemblies before and after reconfiguration are compared with spectra calculated using a structural model that incorporates the core/satellite ratio determined by TEM imaging and estimates of tether length based upon prior measurements of interparticle separation in DNA linked nanoparticle networks. A strong correspondence between measured and simulated difference spectra validates the structural models that link the observed plasmon modulation with DNA nanostructure reconfiguration.
在由可重构DNA纳米结构连接到50纳米金“核心”颗粒上的13纳米金“卫星”颗粒组成的亚100纳米组件中，研究了等离激元耦合的分子控制。DNA纳米结构从紧凑状态重构为伸展状态会导致组件等离激元共振发生蓝移，这表明颗粒间耦合减少且核心 - 卫星连接变长。将重构前后核心 - 卫星组件的散射光谱与使用结构模型计算的光谱进行比较，该结构模型纳入了通过透射电子显微镜成像确定的核心/卫星比率以及基于先前对DNA连接的纳米颗粒网络中颗粒间间距测量的连接长度估计。实测和模拟差异光谱之间的强烈对应关系验证了将观察到的等离激元调制与DNA纳米结构重构联系起来的结构模型。
