Kim TaeHyung, Park Q-Han
Department of Physics, Korea University, Seoul 02841, Republic of Korea.
Nanophotonics. 2022 Jan 11;11(9):1897-1904. doi: 10.1515/nanoph-2021-0649. eCollection 2022 Apr.
Nanoscale particles and structures hold promise in circular dichroism (CD) spectroscopy for overcoming the weakness of molecular CD signals. Significant effort have been made to characterize nanophotonic CD enhancement and find efficient ways to boost molecular chirality, but the best solution is yet to be found. In this paper, we present a rigorous analytic study of the nanophotonic CD enhancement of typical nanoparticles. We consider metallic and dielectric nanoparticles capped with chiral molecules and analyze the effect of multipolar nanoparticles on the molecular CD. We identify the spectral features of the molecular CD resulting from the electric and magnetic resonances of nanoparticles and suggest better ways to boost molecular chirality. We also clarify the contribution of particle scattering and absorption to the molecular CD and the dependence on particle size. Our work provides an exact analytic approach to nanophotonic CD enhancement and offers a rule for selecting the most efficient particle for sensitive molecular chirality detection.
纳米级颗粒和结构有望在圆二色性（CD）光谱中克服分子CD信号的弱点。人们已经做出了巨大努力来表征纳米光子CD增强并找到增强分子手性的有效方法，但最佳解决方案尚未找到。在本文中，我们对典型纳米颗粒的纳米光子CD增强进行了严格的分析研究。我们考虑了被手性分子包覆的金属和介电纳米颗粒，并分析了多极纳米颗粒对分子CD的影响。我们确定了由纳米颗粒的电和磁共振产生的分子CD的光谱特征，并提出了增强分子手性的更好方法。我们还阐明了颗粒散射和吸收对分子CD的贡献以及对颗粒尺寸的依赖性。我们的工作为纳米光子CD增强提供了一种精确的分析方法，并为选择用于灵敏分子手性检测的最有效颗粒提供了规则。
