Tanriover Ibrahim, Li Yuanwei, Gage Thomas E, Arslan Ilke, Liu Haihua, Mirkin Chad A, Aydin Koray
Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.
ACS Nano. 2024 Oct 15;18(41):28258-28267. doi: 10.1021/acsnano.4c08875. Epub 2024 Oct 1.
Plasmonic nanomaterials, particularly noble metal nanoframes (NFs), are important for applications such as catalysis, biosensing, and energy harvesting due to their ability to enhance localized electric fields and atomic efficiency via localized surface plasmon resonance (LSPR). Yet the fundamental structure-function relationships and plasmonic dynamics of the NFS are difficult to study experimentally and thus far rely predominately on computational methodologies, limiting their utilization. This study leverages the capabilities of ultrafast electron microscopy (UEM), specifically photon-induced near-field electron microscopy (PINEM), to probe the light-matter interactions within plasmonic NF structures. The effects of shape, size, and plasmonic coupling of Pt@Au core-shell NFs on spatial and temporal characteristics of plasmon-enhanced localized electric fields are explored. Importantly, time-resolved PINEM analysis reveals that the plasmonic fields around hexagonal NF prisms exhibit a spatially dependent excitation and decay rate, indicating a nuanced interplay between the spatial geometry of the NF and the temporal evolution of the localized electric field. These results and observations uncover nanophotonic energy transfer dynamics in NFs and highlight their potential for applications in biosensing and photocatalysis.
等离子体纳米材料，特别是贵金属纳米框架（NFs），因其能够通过局域表面等离子体共振（LSPR）增强局域电场和原子效率，在催化、生物传感和能量收集等应用中具有重要意义。然而，NFs的基本结构-功能关系和等离子体动力学很难通过实验进行研究，目前主要依赖于计算方法，这限制了它们的应用。本研究利用超快电子显微镜（UEM）的能力，特别是光子诱导近场电子显微镜（PINEM），来探测等离子体NF结构内的光-物质相互作用。研究了Pt@Au核壳NFs的形状、尺寸和等离子体耦合对等离子体增强局域电场的空间和时间特性的影响。重要的是，时间分辨PINEM分析表明，六边形NF棱镜周围的等离子体场表现出空间依赖性的激发和衰减率，这表明NF的空间几何结构与局域电场的时间演化之间存在细微的相互作用。这些结果和观察揭示了NFs中的纳米光子能量转移动力学，并突出了它们在生物传感和光催化应用中的潜力。
