Enhanced Optical Forces and Tunable LSPR of Ag Triangular Nanoplates for Plasmonic Tweezers
Enhanced Optical Forces and Tunable LSPR of Ag Triangular Nanoplates for Plasmonic Tweezers
复制标题
用于等离激元镊子的银三角形纳米板的增强光学力和可调谐局域表面等离子体共振
DOI：
10.1007/s11468-021-01533-3
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发表时间：
2021-10-05
期刊：
影响因子：
3
通讯作者：
Sun, Xiudong
中科院分区：
文献类型：
--
作者：
Jia, Pengxue;Shi, Hongyan;Sun, Xiudong
在这项工作中，我们提出了一个等离子体平台能够增强电场（E-场）强度，可调LSPR效应，并捕获纳米粒子在不同配置的银三角形纳米片。我们的纳米结构具有更高的结构各向异性（大的纵横比，10：1），其将表面等离子体定位在差距区域，并且具有大的电场增强因子（~850）。Ag纳米片的可调谐近场增强热点支持350 ~ 1200 nm范围内的不同谐振模式，电场分布和陷阱势阱分布也可调控。二聚体的热点增强了30 nm聚苯乙烯纳米颗粒上的光学力（~3.2 nN），功率密度低至1 mW/μm2，显示出出色的捕获特性。具有更高周期对称性的四聚体提供深势阱（~kBT）。它为捕获和操纵纳米级颗粒提供了机会。纳米间隙结构为表面增强拉曼散射、表面增强红外吸收可调谐生物传感器的应用奠定了基础。
In this work, we present a plasmonic platform capable of the enhanced electric field (E-field) intensity, tunable LSPR effect, and trapping nanoparticles in different configurations of Ag triangular nanoplates. Our nanostructures equip the higher structural anisotropy (larger aspect ratio, 10:1), which localize surface plasmons in the gap region and possess the great factor of E-field enhancement (~850). Tunable near-field enhanced hotspots of Ag nanoplates support different resonant modes from 350 to 1200 nm, and the distribution of electric field and trapping potential well can also be manipulated. The hotspots for dimer enhance the optical force (~3.2 nN) on 30-nm polystyrene nanoparticles with a power density as low as 1 mW/μm2, which shows brilliant trapping characteristics. The tetramer with higher periodic symmetry provides a deep potential well (~kBT). It offers opportunities for the trapping and manipulating particles of nanoscale. And the nanogap structures pave a way for applications in surface-enhanced Raman scattering, surface-enhanced infrared absorption tunable biosensors.