State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China.
Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Science. 2021 Mar 26;371(6536):1368-1374. doi: 10.1126/science.abd8576. Epub 2021 Feb 25.
Chiral assemblies of plasmonic nanoparticles are known for strong circular dichroism but not for high optical asymmetry, which is limited by the unfavorable combination of electrical and magnetic field components compounded by strong scattering. Here, we show that these limitations can be overcome by the long-range organization of nanoparticles in a manner similar to the liquid crystals and found in helical assemblies of gold nanorods with human islet amyloid polypeptides. A strong, polarization-dependent spectral shift and the reduced scattering of energy states with antiparallel orientation of dipoles activated in assembled helices increased optical asymmetry -factors by a factor of more than 4600. The liquid crystal-like color variations and the nanorod-accelerated fibrillation enable drug screening in complex biological media. Improvement of long-range order can also provide structural guidance for the design of materials with high optical asymmetry.
手性组装的等离子体纳米粒子由于具有强烈的圆二色性而闻名，但光学不对称性不高，这是由于强烈散射导致的电和磁场分量的不利组合所限制的。在这里，我们表明，通过类似于液晶的方式，在金纳米棒的螺旋组装中与人胰岛淀粉样多肽一起，将纳米粒子进行长程组织，可以克服这些限制。强烈的、与偏振相关的光谱位移以及在组装螺旋中激活的偶极子的反平行取向的能量状态的散射减少，使光学不对称性增加了 4600 多倍。类似于液晶的颜色变化和纳米棒加速的纤颤使药物筛选能够在复杂的生物介质中进行。远程有序的改善也可以为具有高光学不对称性的材料设计提供结构指导。
