Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.
Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198, Japan.
Sci Rep. 2017 Jan 3;7:39720. doi: 10.1038/srep39720.
We study theoretically the bio-sensing capabilities of metal nanowire surface plasmons. As a specific example, we couple the nanowire to specific sites (bacteriochlorophyll) of the Fenna-Matthews-Olson (FMO) photosynthetic pigment protein complex. In this hybrid system, we find that when certain sites of the FMO complex are subject to either the suppression of inter-site transitions or are entirely disconnected from the complex, the resulting variations in the excitation transfer rates through the complex can be monitored through the corresponding changes in the scattering spectra of the incident nanowire surface plasmons. We also find that these changes can be further enhanced by changing the ratio of plasmon-site couplings. The change of the Fano lineshape in the scattering spectra further reveals that "site 5" in the FMO complex plays a distinct role from other sites. Our results provide a feasible way, using single photons, to detect mutation-induced, or bleaching-induced, local defects or modifications of the FMO complex, and allows access to both the local and global properties of the excitation transfer in such systems.
我们从理论上研究了金属纳米线表面等离激元的生物传感能力。作为一个具体的例子，我们将纳米线与 Fenna-Matthews-Olson (FMO) 光合作用色素蛋白复合物的特定部位（细菌叶绿素）耦合。在这个混合系统中，我们发现当 FMO 复合物的某些部位受到抑制或与复合物完全断开时，通过复合物的激发转移速率的变化可以通过入射纳米线表面等离激元的散射光谱的相应变化来监测。我们还发现，通过改变等离激元-位点耦合的比例，这些变化可以进一步增强。散射光谱中的 Fano 线形状的变化进一步表明，FMO 复合物中的“位点 5”与其他位点具有明显不同的作用。我们的结果提供了一种可行的方法，使用单光子来检测 FMO 复合物中突变诱导或漂白诱导的局部缺陷或修饰，并允许访问此类系统中激发转移的局部和全局性质。
