Firmanti Metya Indah, Ha Ji Won
Department of Chemistry, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan, 44610, South Korea.
Energy Harvest-Storage Research Center (EHSRC), University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan, South Korea.
Sci Rep. 2024 Aug 30;14(1):20182. doi: 10.1038/s41598-024-71141-8.
Herein, we investigated the distinctive scattering properties exhibited by single gold nanorods coated with palladium (AuNRs@Pd), with variations in the Pd shell thicknesses and morphologies. AuNRs@Pd were synthesized through bottom-up epitaxial Pd growth using two different concentrations of Pd precursor. These single AuNRs@Pd displayed the characteristic of subradiant and superradiant localized surface plasmon resonance peaks, characterized by a noticeable gap marked by a Fano dip. We revealed the effect of local refractive index (RI) on the subradiant and superradiant peak energies, as well as the Fano dip in the scattering spectra of AuNRs@Pd with different Pd shell thicknesses. We demonstrated the applicability of the inflection points (IFs) method on detecting peaks and dip changes across different RIs. Thin AuNRs@Pd displayed more pronounced sensitivity to peak shifts in response to variations in local RIs compared to thick AuNRs@Pd. In contrast, thick AuNRs@Pd exhibited greater sensitivity to changes in curvature near the subradiant and superradiant peak energies rather than peak shift sensitivity across different local RIs. Moreover, the Fano dip shift was more noticeable in thick AuNRs@Pd compared to thin AuNRs@Pd across different local RIs. Therefore, we provided new insight into the RI sensitivity on subradiant, superradiant, and Fano resonance modes in single AuNRs@Pd.
在此，我们研究了包覆钯的单根金纳米棒（AuNRs@Pd）所呈现的独特散射特性，以及钯壳层厚度和形态的变化情况。通过使用两种不同浓度的钯前驱体，采用自下而上的外延钯生长法合成了AuNRs@Pd。这些单根AuNRs@Pd表现出亚辐射和超辐射局域表面等离子体共振峰的特性，其特征是由法诺凹陷标记的明显间隙。我们揭示了局部折射率（RI）对不同钯壳层厚度的AuNRs@Pd的亚辐射和超辐射峰能量以及散射光谱中法诺凹陷的影响。我们证明了拐点（IFs）方法在检测不同RI下的峰和凹陷变化方面的适用性。与厚的AuNRs@Pd相比，薄的AuNRs@Pd对局部RI变化引起的峰位移表现出更明显的敏感性。相反，厚的AuNRs@Pd对亚辐射和超辐射峰能量附近的曲率变化表现出更大的敏感性，而不是对不同局部RI下的峰位移敏感性。此外，在不同局部RI下，厚的AuNRs@Pd中的法诺凹陷位移比薄的AuNRs@Pd更明显。因此，我们为单根AuNRs@Pd中亚辐射、超辐射和法诺共振模式的RI敏感性提供了新的见解。
