Structural characterization and plasmonic properties of two-dimensional arrays of hydrophobic large gold nanoparticles fabricated by Langmuir-Blodgett technique
Structural characterization and plasmonic properties of two-dimensional arrays of hydrophobic large gold nanoparticles fabricated by Langmuir-Blodgett technique
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DOI：
10.1016/j.apsusc.2017.01.304
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发表时间：
2017-05-15
影响因子：
6.7
通讯作者：
Yamada, Sunao
中科院分区：
文献类型：
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作者：
Ishida, Takuya;Tachikiri, Yuki;Yamada, Sunao
利用Langmuir-Blodgett(LB)方法，我们成功地制备了直径分别为17、28和48 nm的大颗粒金纳米颗粒的二维阵列。虽然金纳米颗粒的大小是控制二维阵列光学性质的重要因素之一，但仅有小于20 nm的颗粒尺寸被报道过。这是首次报道了由疏水的AuNP组成的自下而上的二维阵列的制备，其直径接近50 nm，其尺寸有望获得最大的近场效应。用我们的方法制备的十八烷基硫醇封端的AuNPs(ODT-AuNPs)在完全干燥后仍可以在氯仿中重新分散，实现了胶体氯仿溶液在水面上的铺展。因此，以水为亚相，聚乙二醇为两亲性试剂，可以在铟锡氧化物衬底上制备出致密堆积的二维ODT-AuNPs LB膜。由于疏水的AuNP与水的亲和力增强，聚乙二醇酯在均匀形成致密堆积的薄膜方面起到了重要作用。吸收光谱表明，通过粒子间等离子体激元耦合产生的等离子体激元振荡的共振波长明显与粒子尺寸相关，而不是与沉积密度相关。(C)2017爱思唯尔B.V.保留所有权利。
We have succeeded in fabricating two-dimensional (2D) arrays of larger gold nanoparticles (AuNPs) (diameters 17, 28, and 48 nm) by Langmuir-Blodgett (LB) method. Although the particle size of AuNPs is one of the most important factors in order to control the optical properties of 2D arrays, there have been reported only the size of less than similar to 20nm. This is a first report on the bottom-up fabrication of 2D arrays consisting of hydrophobic AuNP with the diameter of similar to 50 nm, of which the size is expected to obtain maximum near-field effects. Octadecylthiolate-capped AuNPs (ODT-AuNPs) which were prepared by our method could be re-dispersed in chloroform even after drying completely, realizing the spreading of the colloidal chloroform solution onto the water surface. Accordingly, densely-packed 2D LB films of ODT-AuNPs could be fabricated on an indium-tin-oxide substrate, when water as the sub phase and polyethylene glycol (PEG) as an amphiphilic agent were used. PEG played an important role to form densely-packed film uniformly due to increasing affinity between hydrophobic AuNP and water. Absorption spectra of the films revealed that the resonance wavelengths of plasmon oscillation through interparticle plasmon coupling were clearly correlated with the particle sizes rather than deposition densities. (C) 2017 Elsevier B.V. All rights reserved.