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Dispersible Gold Nanorod Dimers with Sub-5 nm Gaps as Local Amplifiers for Surface-Enhanced Raman Scattering
journal contribution
posted on 2016-02-20, 17:28 authored by Kyle D. Osberg, Matthew Rycenga, Nadine Harris, Abrin
L. Schmucker, Mark R. Langille, George C. Schatz, Chad A. MirkinWe report the synthesis of solution-dispersible, 35 nm
diameter
gold nanorod dimers with gaps as small as ∼2 nm for surface-enhanced
Raman scattering (SERS). Using on-wire lithography (OWL), we prepared
tailorable dimers in high yield and high monodispersity (∼96%
dimers) that produce both large and reproducible SERS signals with
enhancement factors of (6.8 ± 0.7) × 108 for
single dimers in air and 1.2 × 106 for ensemble-averaged
solution measurements. Furthermore, we show that these structures,
which are the smallest ever made by OWL, can be used to detect molecules
on flat surfaces and in aqueous solutions. When combined, these attributes
with respect to sensitivity, reproducibility, and tailorability lead
to a novel and powerful local amplification system for SERS applications.