Plasmonic All-Frame-Faceted Octahedral Nanoframes with Eight Engraved Y-Shaped Hot Zones

Abstract

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 (i.e., 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.

Multiple Stepwise Synthetic Pathways toward Complex Plasmonic 2D and 3D Nanoframes for Generation of Electromagnetic Hot Zones in a Single Entity

“…2,51,52 By mirroring a strategy used in photolithography, we have reported a bottom-up nanopatterning method for all-frame-faceted octahedral NFs where Pt tripod NFs were patterned on every facet of eight octahedral NPs (Figure 7a). 53 The critical step for the Y-shape-engraved octahedral NFs is to pattern the eight faces (i.e., (111) facets) of Au octahedral NPs to have 24 curved edge lines, which we call "chemical carving". 5 Such a complicated engraving process can be achieved by precisely tuning the electrochemical potential of a solution (E chem ) through a combination of experimental parameters such as temperature, pH, reducing agent, and surfactant concentration.…”

Designing plasmonically integrated nanoreactors for efficient catalysis

“…The strategies for designing advanced plasmonically intricate nanoreactors require a certain degree of morphological uniqueness so that they are able to harvest the maximum amount of light energy. 47,48 Several studies on the morphological modulation of plasmonic nanoparticles have shown that the localized surface plasmon resonance (LSPR) depends on the size and shape of the NCs. For instance, LSPR can be amplified significantly in the case of anisotropic nanostructures (i.e., cubes, prisms, and stars) compared with isotropic ones (i.e., spheres).…”

DNA‐Dependent Prussian Blue Nanoflowers for Biosensing, Catalysis and Imaging

“…[ 1,2 ] This phenomenon has been validated on various nanomaterials, including gold nanomaterials, [ 3,4 ] silver nanomaterials, [ 5,6 ] carbon nanomaterials, [ 7 ] and bimetallic nanomaterials. [ 8 ] Among all those nanomaterials, gold nanomaterials have been the center of interest in terms of their morphology and properties. [ 9,10 ] The photothermal effect, catalytic activity, and plasmonic activity of gold nanomaterials were proved to be highly dependent on their geometry and size.…”