Department of Chemistry, University of Sheffield , Brook Hill, Sheffield S3 7HF, U.K.
Department of Molecular Biology and Biotechnology, University of Sheffield , Western Bank, Sheffield S10 2TN, U.K.
Nano Lett. 2016 Nov 9;16(11):6850-6856. doi: 10.1021/acs.nanolett.6b02661. Epub 2016 Oct 10.
Gold nanostructure arrays exhibit surface plasmon resonances that split after attaching light harvesting complexes 1 and 2 (LH1 and LH2) from purple bacteria. The splitting is attributed to strong coupling between the localized surface plasmon resonances and excitons in the light-harvesting complexes. Wild-type and mutant LH1 and LH2 from Rhodobacter sphaeroides containing different carotenoids yield different splitting energies, demonstrating that the coupling mechanism is sensitive to the electronic states in the light harvesting complexes. Plasmon-exciton coupling models reveal different coupling strengths depending on the molecular organization and the protein coverage, consistent with strong coupling. Strong coupling was also observed for self-assembling polypeptide maquettes that contain only chlorins. However, it is not observed for monolayers of bacteriochlorophyll, indicating that strong plasmon-exciton coupling is sensitive to the specific presentation of the pigment molecules.
金纳米结构阵列表现出表面等离激元共振，在附着来自紫色细菌的光捕获复合物 1 和 2（LH1 和 LH2）后，这些共振会发生分裂。这种分裂归因于局域表面等离激元共振与光捕获复合物中的激子之间的强耦合。来自球形红杆菌的野生型和突变型 LH1 和 LH2 含有不同的类胡萝卜素，产生不同的分裂能，表明耦合机制对光捕获复合物中的电子态敏感。等离激元-激子耦合模型揭示了不同的耦合强度取决于分子组织和蛋白质覆盖，与强耦合一致。自组装多肽模型也观察到了强耦合，这些模型仅包含叶绿素。然而，单层细菌叶绿素却没有观察到，这表明强等离激元-激子耦合对色素分子的特定呈现方式敏感。
