Self-assembly of functionalized nanoparticles (NPs) provides a unique class of nanomaterials for exploring and utilizing quantum-plasmonic effects that occur if the interparticle separation between NPs approaches a few nanometers and below. We review recent theoretical and experimental studies of plasmon coupling in self-assembled NP structures that contain molecular linkers between the NPs. Charge transfer through the interparticle gap of an NP dimer results in a significant blue-shift of the bonding dipolar plasmon (BDP) mode relative to classical electromagnetic predictions, and gives rise to new coupled plasmon modes, the so-called charge transfer plasmon (CTP) modes. The blue-shift of the plasmon spectrum is accompanied by a weakening of the electromagnetic field in the gap of the NPs. Due to an optical far-field signature that is sensitive to charge transfer across the gap, plasmonic molecules represent a sensor platform for detecting and characterizing gap conductivity in an optical fashion and for characterizing the role of molecules in facilitating the charge transfer across the gap.

中文翻译：

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分子连接的等离子体纳米颗粒组件中电荷转移的光谱特征

功能化纳米颗粒 (NP) 的自组装提供了一类独特的纳米材料，用于探索和利用纳米颗粒之间的颗粒间间距接近几纳米及以下时发生的量子等离子体效应。我们回顾了最近关于自组装纳米颗粒结构中等离子体耦合的理论和实验研究，这些结构在纳米颗粒之间含有分子连接体。通过 NP 二聚体颗粒间间隙的电荷转移导致键合偶极等离子体 (BDP) 模式相对于经典电磁预测发生显着蓝移，并产生新的耦合等离子体模式，即所谓的电荷转移等离子体 (CTP) ) 模式。等离激元光谱的蓝移伴随着纳米粒子间隙中电磁场的减弱。由于光学远场特征对跨越间隙的电荷转移敏感，等离子体分子代表了一个传感器平台，用于以光学方式检测和表征间隙电导率，以及表征分子在促进跨越间隙的电荷转移中的作用。