Kim Jeongwon, Hilal Hajir, Haddadnezhad MohammadNavid, Lee Jaewon, Park Woocheol, Park Woongkyu, Lee Joong-Wook, Jung Insub, Park Sungho
Department of Chemistry, Sungkyunkwan University, Suwon 16419, South Korea.
Medical & Bio Photonics Research Center, Korea Photonics Technology Institute (KOPTI), Gwangju 61007, South Korea.
ACS Nano. 2022 Jun 28;16(6):9214-9221. doi: 10.1021/acsnano.2c01543. Epub 2022 Apr 21.
We report the synthesis of all-frame-faceted octahedral nanoframes containing eight Y-shaped hot zones in a single entity where electromagnetic near-field focusing can be maximized. To realize such state-of-the-art complex nanoframes, a series of multiple stepwise bottom-up processes were executed by exploiting Au octahedral nanoparticles as the initial template. By rationally controlling the chemical reactivity of different surface facets (, vertexes, edges, and terraces), the Au octahedral nanoparticles went through controlled shape transformations, leading to Au-engraved nanoparticles wherein 24 edges wrap the octahedral Au nanoparticle core. Those edges were then selectively decorated with Pt, leading to the formation of eight Pt tripods in a single entity. After etching the central Au, 3D Pt tripod frame-faceted octahedral nanoframes were achieved with high integrity. By harnessing the obtained Pt nanoframes as a scaffold, AuAg alloy-based plasmonic all-frame-faceted nanoframes were obtained after the co-reduction of Ag and Au, which generated multiple hot zones within multiple surface intra-nanogaps, creating a single-particle, surface-enhanced Raman spectroscopy enhancer platform.
我们报道了全框架刻面八面体纳米框架的合成，该纳米框架在单个实体中包含八个Y形热点区域，可实现电磁近场聚焦的最大化。为了实现这种先进的复杂纳米框架，通过利用金八面体纳米颗粒作为初始模板执行了一系列多步自下而上的过程。通过合理控制不同表面小面（顶点、边缘和平坦面）的化学反应性，金八面体纳米颗粒经历了可控的形状转变，形成了金刻蚀纳米颗粒，其中24条边缘包裹着八面体金纳米颗粒核心。然后这些边缘被选择性地用铂修饰，导致在单个实体中形成八个铂三脚架。蚀刻掉中心的金后，获得了具有高完整性的三维铂三脚架框架刻面八面体纳米框架。通过将获得的铂纳米框架用作支架，在银和金共还原后获得了基于金-银合金的等离子体全框架刻面纳米框架，这在多个表面纳米间隙内产生了多个热点区域，创建了一个单颗粒表面增强拉曼光谱增强平台。
