Magnetic Alignment for Plasmonic Control of Gold Nanorods Coated with Iron Oxide Nanoparticles
Magnetic Alignment for Plasmonic Control of Gold Nanorods Coated with Iron Oxide Nanoparticles
复制标题
氧化铁纳米粒子涂覆的金纳米棒的等离激元控制的磁对准
DOI：
10.1002/adma.202203366
复制
发表时间：
2022
影响因子：
29.4
通讯作者：
Tracy, Joseph B.
中科院分区：
文献类型：
--
作者：
Rizvi, Mehedi H.;Wang, Ruosong;Schubert, Jonas;Crumpler, William D.;Rossner, Christian;Oldenburg, Amy L.;Fery, Andreas;Tracy, Joseph B.
等离子体纳米粒子可以用磁场操纵，对先进的光学应用、诊断、成像和治疗很感兴趣。金纳米棒的排列产生强烈的极化相关消光，并且使用磁场很有吸引力，因为它们通过空间起作用并且可以快速切换。在这项工作中，将阳离子聚乙烯亚胺功能化的超顺磁性fe3o4纳米颗粒（NPs）沉积在涂有牛血清白蛋白的阴离子金纳米棒表面。通过混合获得的磁性金纳米棒（MagGNRs）保持了等离子体金纳米棒的独特光学特性，并且受磁性覆盖层的干扰最小。全面表征了各向异性金纳米棒磁芯上磁偶极相互作用产生的磁取向，包括结构表征和纵向表面等离子体共振的增强（抑制）以及与磁场平行（正交）的光极化对横向表面等离子体共振的抑制（增强）。maggnr还可以在旋转磁场中驱动，以至少17赫兹的频率旋转。对于适当大的金纳米棒（148 nm长）和Fe3O4NPs （13.4 nm直径），即使在适度（<500 Oe）的磁场中也可能出现明显的对齐。一个解析模型提供了一个统一的理解磁纳米管的磁向。
Plasmonic nanoparticles that can be manipulated with magnetic fields are of interest for advanced optical applications, diagnostics, imaging, and therapy. Alignment of gold nanorods yields strong polarization‐dependent extinction, and use of magnetic fields is appealing because they act through space and can be quickly switched. In this work, cationic polyethyleneimine‐functionalized superparamagnetic Fe3O4nanoparticles (NPs) are deposited on the surface of anionic gold nanorods coated with bovine serum albumin. The magnetic gold nanorods (MagGNRs) obtained through mixing maintain the distinct optical properties of plasmonic gold nanorods that are minimally perturbed by the magnetic overcoating. Magnetic alignment of the MagGNRs arising from magnetic dipolar interactions on the anisotropic gold nanorod core is comprehensively characterized, including structural characterization and enhancement (suppression) of the longitudinal surface plasmon resonance and suppression (enhancement) of the transverse surface plasmon resonance for light polarized parallel (orthogonal) to the magnetic field. The MagGNRs can also be driven in rotating magnetic fields to rotate at frequencies of at least 17 Hz. For suitably large gold nanorods (148 nm long) and Fe3O4NPs (13.4 nm diameter), significant alignment is possible even in modest (<500 Oe) magnetic fields. An analytical model provides a unified understanding of the magnetic alignment of MagGNRs.