Abstract 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.

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在经典和量子耦合机制中使用等离子体纳米立方体链的高灵敏度分子传感

摘要 一维等离子体纳米粒子阵列具有有趣的光学特性，可用于许多应用，包括分子传感。在本文中，我们首先研究了边长为 21 nm 的金和银等离子体纳米立方体链中的等离子体耦合行为，这些纳米立方体以面对面和边缘到边缘的配置以大间距（8.5 nm）排列，其中经典的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缘到边缘的配置时，观察到灵敏度因子的增加，但有一些例外。此外，具有亚纳米粒子间距（0.2 nm）的边对边和面对面组装的金纳米立方体的线性链，在隧道诱导的电荷转移等离子体 (tCTP) 的影响变得显着的情况下，使用量子校正模型进行了研究。与面对面取向相比，光学特性的变化在边对边配置中更为突出。我们的结果表明，线性组装的纳米粒子中的等离子体耦合在亚纳米粒子间距下变得极其重要。它可以显着改变纳米立方体链的光学特性，尤其是谱线形状和电场分布，这可能有助于为化学和生物传感应用设计更先进的传感设备。在边缘到边缘配置中，光学特性的变化更为突出。我们的结果表明，线性组装的纳米粒子中的等离子体耦合在亚纳米粒子间距下变得极其重要。它可以显着改变纳米立方体链的光学特性，尤其是谱线形状和电场分布，这可能有助于为化学和生物传感应用设计更先进的传感设备。在边缘到边缘配置中，光学特性的变化更为突出。我们的结果表明，线性组装的纳米粒子中的等离子体耦合在亚纳米粒子间距下变得极其重要。它可以显着改变纳米立方体链的光学特性，尤其是谱线形状和电场分布，这可能有助于为化学和生物传感应用设计更先进的传感设备。