Magnetic Plasmon Networks Programmed by Molecular Self‐Assembly
Magnetic Plasmon Networks Programmed by Molecular Self‐Assembly
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DOI：
10.1002/adma.201901364
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发表时间：
2019-05
影响因子：
29.4
通讯作者：
Pengfei Wang;Ji‐Hyeok Huh;Jaewon Lee;Kwangjin Kim;Kyung Jin Park;Seungwoo Lee;Yonggang Ke
中科院分区：
文献类型：
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作者：
Pengfei Wang;Ji‐Hyeok Huh;Jaewon Lee;Kwangjin Kim;Kyung Jin Park;Seungwoo Lee;Yonggang Ke
磁场的纳米级操控一直是等离子体学和超材料领域的长期追求，因为它可以实现一系列吸引人的光学特性，例如高灵敏度圆二色性、定向散射和低折射率材料。受芳香族分子自然磁性的启发，等离激元纳米颗粒（NP）的环状簇被认为是一种有前景的结构，具有诱导非自然磁性，特别是在可见频率下。然而，将等离子体纳米粒子组装成具有强可见磁性的复杂网络仍然具有挑战性。在这里，引入了基于DNA折纸的策略来实现纳米粒子的分子自组装，形成复杂的磁性结构，表现出包括反铁磁性、纯磁性法诺共振和磁性表面等离子体极化激元在内的新兴特性。基本构建块是由六个 AuNP 种子组成的金 NP (AuNP) 环，以纳米精度排列在 DNA 折纸框架上。随后 AuNP 环的分层组装导致形成簇和聚合物链的高阶网络。银在 AuNP 种子上的原位生长诱导了强烈的涌现等离子体特性。这项工作可能有助于开发一种可调谐且可扩展的基于 DNA 的策略，用于组装光磁电路以及高保真度的等离子体超材料。
Nanoscale manipulation of magnetic fields has been a long‐term pursuit in plasmonics and metamaterials, as it can enable a range of appealing optical properties, such as high‐sensitivity circular dichroism, directional scattering, and low‐refractive‐index materials. Inspired by the natural magnetism of aromatic molecules, the cyclic ring cluster of plasmonic nanoparticles (NPs) has been suggested as a promising architecture with induced unnatural magnetism, especially at visible frequencies. However, it remains challenging to assemble plasmonic NPs into complex networks exhibiting strong visible magnetism. Here, a DNA‐origami‐based strategy is introduced to realize molecular self‐assembly of NPs forming complex magnetic architectures, exhibiting emergent properties including anti‐ferromagnetism, purely magnetic‐based Fano resonances, and magnetic surface plasmon polaritons. The basic building block, a gold NP (AuNP) ring consisting of six AuNP seeds, is arranged on a DNA origami frame with nanometer precision. The subsequent hierarchical assembly of the AuNP rings leads to the formation of higher‐order networks of clusters and polymeric chains. Strong emergent plasmonic properties are induced by in situ growth of silver upon the AuNP seeds. This work may facilitate the development of a tunable and scalable DNA‐based strategy for the assembly of optical magnetic circuitry, as well as plasmonic metamaterials with high fidelity.