ScholarWorks@성균관대학교

초록

Herein, we present a synthetic strategy for fabricating plasmonic particle-in-a-frame nanostructures in which a solid Au nanosphere (NS) is enclosed within a truncated octahedral (TOh) dual-rim Au nanoframe (DNF). Owing to their concentric, light-focusing architecture and broadband electromagnetic field enhancement, these geometrically complex NPs are referred to as "plasmonic nano-auracles" (PNAs). Unlike conventional solid NSs and hollow TOh monorim nanoframes (MNFs), which lack core structures and internal surface gaps, the sphere-in-dual-rim nanoframes (SIDNFs) architecture uniquely integrates both core-related intra- and interparticle gaps as well as intraframe surface gaps due to its intricate internal structure. This multigap configuration enables the simultaneous generation of strong three-dimensional (3D) electromagnetic nanocavities between the inner Au core and the outer frame, along with two-dimensional (2D) hot spots on the dual-rim facets of the TOh frame. The enclosed Au NS performs dual functions. It provides an additional surface for analyte attachment, unlike hollow counterparts, and also serves as an efficient light absorber that facilitates strong, multimodal plasmonic coupling with the surrounding frame. This internal coupling is highly effective across a broad range of excitation wavelengths, resulting in significantly enhanced near-field confinement and improved cavity-enhanced Raman signals under both 633 and 785 nm laser excitation. The synergistic combination of large surface area, multiple plasmonic coupling, and wavelength-selective enhancement provide excellent light-trapping capabilities to the plasmonic nanoauracle. These features establish it as a promising platform for ultrasensitive molecular detection and advanced optical sensing.

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