High-sensitivity molecular sensing using plasmonic nanocube chains in classical and quantum coupling regimes
High-sensitivity molecular sensing using plasmonic nanocube chains in classical and quantum coupling regimes
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DOI：
10.1016/j.nantod.2017.10.009
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发表时间：
2017-12
期刊：
影响因子：
17.4
通讯作者：
N. Hooshmand;N. Hooshmand;H. Mousavi;Sajanlal R. Panikkanvalappil;A. Adibi;M. El-Sayed
中科院分区：
文献类型：
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作者：
N. Hooshmand;N. Hooshmand;H. Mousavi;Sajanlal R. Panikkanvalappil;A. Adibi;M. El-Sayed
一维等离子体纳米颗粒阵列具有耐人寻味的光学特性，可用于包括分子传感在内的许多应用。本文首先研究了边长为21 nm的金银等离子体纳米立方体在大间距(8.5 nm)下的等离子体耦合行为，其中经典电磁耦合占主导地位。有趣的是，当增加链中纳米立方体的数量并将它们定向为边到边的构型时，可以观察到灵敏度因子的增加，但有几个例外。此外，利用量子修正模型研究了具有亚纳米粒子间距(0.2 nm)的边到边和面对面组装的金纳米立方体的线性链，其中隧道诱导电荷转移等离子体(TCTPs)的影响变得显著。与面对面取向相比，边缘-边缘构型的光学性质变化更为显著。我们的结果表明，在亚纳米粒子间距范围内，线性组装的纳米粒子中的等离子体耦合变得非常重要。它可以显著改变纳米立方体链的光学性质，特别是谱线形状和电场分布，这可能有助于设计更先进的传感器件，用于化学和生物传感应用。
One-dimensional plasmonic nanoparticle arrays have intriguing optical properties that can be utilized in a number of applications, including molecular sensing. In this paper, firstly, we studied the plasmonic coupling behavior in chains of gold and silver plasmonic nanocubes of 21 nm edge length arranged in both face-to-face and edge-to-edge configurations at large separation distance (8.5 nm), where the classical electromagnetic coupling is dominant. Interestingly, an increase in the sensitivity factor was observed when increasing the number of nanocubes in the chain and by orienting them in edge-to-edge configuration, with a few exceptions. Additionally, linear chains of edge-to-edge and face-to-face assembled gold nanocube with sub-nanometer interparticle distances (0.2 nm), where the effect of tunneling-induced charge transfer plasmons (tCTPs) becomes significant, was studied using a quantum-corrected model. In comparison to the face-to-face orientation, the changes in optical properties were more prominent in the edge-to-edge configuration. Our results suggest that plasmonic coupling in linearly assembled nanoparticles becomes extremely important at sub-nanometer interparticle distances. It can significantly modify the optical properties of the nanocubes chains, especially spectral line shape and electric-field distribution, which might help designing more advanced sensing devices for chemical and bio-sensing applications.