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|Title:||Precision synthesis : designing hot spots over hot spots via selective gold deposition on silver octahedra edges||Authors:||Hegde, Ravi S.
Tjiu, Weng Weei
Ling, Xing Yi
Lee, Yih Hong
|Keywords:||DRNTU::Science::Physics||Issue Date:||2014||Source:||Liu, Y., Pedireddy, S., Lee, Y. H., Hegde, R. S., Tjiu, W. W., Cui, Y., et al. (2014). Precision synthesis : designing hot spots over hot spots via selective gold deposition on silver octahedra edges. Small, 10(23), 4940-4950.||Series/Report no.:||Small||Abstract:||A major challenge in plasmonic hot spot fabrication is to efficiently increase the hot spot volumes on single metal nanoparticles to generate stronger signals in plasmon-enhanced applications. Here, the synthesis of designer nanoparticles, where plasmonic-active Au nanodots are selectively deposited onto the edge/tip hot spot regions of Ag nanoparticles, is demonstrated using a two-step seed-mediated precision synthesis approach. Such a “hot spots over hot spots” strategy leads to an efficient enhancement of the plasmonic hot spot volumes on single Ag nanoparticles. Through cathodoluminescence hyperspectral imaging of these selective edge gold-deposited Ag octahedron (SEGSO), the increase in the areas and emission intensities of hot spots on Ag octahedra are directly visualized after Au deposition. Single-particle surface-enhanced Raman scattering (SERS) measurements demonstrate 10-fold and 3-fold larger SERS enhancement factors of the SEGSO as compared to pure Ag octahedra and non-selective gold-deposited Ag octahedra (NSEGSO), respectively. The experimental results corroborate well with theoretical simulations, where the local electromagnetic field enhancement of our SEGSO particles is 15-fold and 1.3-fold stronger than pure Ag octahedra and facet-deposited particles, respectively. The growth mechanisms of such designer nanoparticles are also discussed together with a demonstration of the versatility of this synthetic protocol.||URI:||https://hdl.handle.net/10356/103960
|ISSN:||1613-6810||DOI:||10.1002/smll.201401242||Rights:||© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.||Fulltext Permission:||none||Fulltext Availability:||No Fulltext|
|Appears in Collections:||SPMS Journal Articles|
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