Institute of Fundamental and Frontier Sciences , University of Electronic Science and Technology of China , Chengdu 610054 , China.
Department of Physics and Astronomy , Ohio University , Athens , Ohio 45701 , United States.
J Am Chem Soc. 2018 Sep 19;140(37):11763-11770. doi: 10.1021/jacs.8b06526. Epub 2018 Sep 6.
The ability to dynamically tune the self-assembled structures of nanoparticles is of significant interest in the fields of chemistry and material studies. However, it continues to be challenging to dynamically tune the chiral superstructures of nanoparticles and actively switch the chiral optical properties thereof. Here, we dynamically controlled a gold nanorod 3D chiral plasmonic superstructure (a stair helix with a pinwheel end view) templated by a DNA origami supramolecular polymer, using DNA-toehold-mediated conformational change in the DNA template. The gold nanorod chiral plasmonic helix was controllably reconfigured between a tightly folded state (with a small inter-rod angle) and an extended state (with a wide inter-rod angle) of the same handedness, or between two mirror-image-like structures of opposite handedness. As a result, the chiral plasmonic properties of the gold nanorod helix superstructures, in terms of the circular dichroism amplitude, peak response frequency, and signature of chirality, were actively switched upon the DNA-guided structural reconfiguration. We envision that the strategy demonstrated here will boost the advancement of reconfigurable chiral materials with increased complexity for active light control applications through rational molecular design and predictable self-assembly procedures.
动态调控纳米粒子自组装结构在化学和材料研究领域具有重要意义。然而，动态调控纳米粒子的手性超结构并主动切换其手性光学性质仍然具有挑战性。在这里，我们使用 DNA 适体介导的 DNA 模板构象变化，动态控制了由 DNA 折纸超分子聚合物模板化的金纳米棒 3D 手性等离子体超结构（末端呈风车状的阶梯螺旋）。金纳米棒手性等离子体螺旋可以在相同手性的紧密折叠状态（棒间角度较小）和展开状态（棒间角度较宽）之间，或者在两个互为镜像的相反手性结构之间进行可控的重新配置。因此，在手性等离子体超结构中，金纳米棒的手性光学性质（圆二色性幅度、峰响应频率和手性特征）在 DNA 引导的结构重配置时得到了主动切换。我们设想，通过合理的分子设计和可预测的自组装程序，这里展示的策略将推动具有更高复杂性的可重构手性材料的发展，从而实现主动光控制应用。
