Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK.
Nanoscale. 2018 Jul 13;10(27):13064-13073. doi: 10.1039/c8nr02144a.
In strong plasmon-exciton coupling, a surface plasmon mode is coupled to an array of localized emitters to yield new hybrid light-matter states (plexcitons), whose properties may in principle be controlled via modification of the arrangement of emitters. We show that plasmon modes are strongly coupled to synthetic light-harvesting maquette proteins, and that the coupling can be controlled via alteration of the protein structure. For maquettes with a single chlorin binding site, the exciton energy (2.06 ± 0.07 eV) is close to the expected energy of the Qy transition. However, for maquettes containing two chlorin binding sites that are collinear in the field direction, an exciton energy of 2.20 ± 0.01 eV is obtained, intermediate between the energies of the Qx and Qy transitions of the chlorin. This observation is attributed to strong coupling of the LSPR to an H-dimer state not observed under weak coupling.
在强等离子激元-激子耦合中，表面等离子体模式与局域发射器阵列耦合，产生新的混合光物质态（激子），其性质原则上可以通过改变发射器的排列来控制。我们表明，等离子体模式与合成光捕获模型蛋白强烈耦合，并且可以通过改变蛋白质结构来控制耦合。对于具有单个叶绿素结合位点的模型，激子能量（2.06 ± 0.07 eV）接近 Qy 跃迁的预期能量。然而，对于在电场方向上共线的含有两个叶绿素结合位点的模型，获得了 2.20 ± 0.01 eV 的激子能量，介于叶绿素的 Qx 和 Qy 跃迁能量之间。这一观察结果归因于 LSPR 与 H-二聚体状态的强耦合，在弱耦合下观察不到这种状态。
