Lee Jaebeom, Hernandez Pedro, Lee Jungwoo, Govorov Alexander O, Kotov Nicholas A
Department of Chemical Engineering, Materials Science and Engineering, and Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
Nat Mater. 2007 Apr;6(4):291-5. doi: 10.1038/nmat1869. Epub 2007 Mar 25.
Electronic interactions at the nanoscale represent one of the fundamental problems of nanotechnology. Excitons and plasmons are the two most typical excited states of nanostructures, which have been shown to produce coupled electronic systems. Here, we explore these interactions for the case of nanowires with mobile excitons and nanoparticles with localized plasmons and describe the theoretical formalism, its experimental validation and the potential practical applications of such nanoscale systems. Theory predicts that emission of coupled excitations in nanowires with variable electronic confinement is stronger, shorter and blue-shifted. These predictions were confirmed with a high degree of accuracy in molecular spring assemblies of CdTe nanowires and Au nanoparticles, where we can reversibly change the distance between the exciton and the plasmon. The prepared systems were made protein-sensitive by incorporating antibodies in the molecular springs. Modulation of exciton-plasmon interactions can serve as a wavelength-based biodetection tool, which can resolve difficulties in the quantification of luminescence intensity for complex media and optical pathways.
纳米尺度的电子相互作用是纳米技术的基本问题之一。激子和等离激元是纳米结构的两种最典型的激发态，已被证明能产生耦合电子系统。在此，我们针对具有移动激子的纳米线和具有局域等离激元的纳米粒子的情况探索这些相互作用，并描述理论形式、其实验验证以及此类纳米尺度系统的潜在实际应用。理论预测，具有可变电子限制的纳米线中耦合激发的发射更强、更短且蓝移。这些预测在CdTe纳米线和Au纳米粒子的分子弹簧组件中得到了高度精确的证实，在该组件中我们可以可逆地改变激子和等离激元之间的距离。通过在分子弹簧中掺入抗体，制备的系统对蛋白质敏感。激子 - 等离激元相互作用的调制可作为一种基于波长的生物检测工具，它可以解决复杂介质和光学路径中发光强度定量的难题。
