The surface-enhanced Raman scattering properties of nanoporous gold prepared by the dealloying technique have been investigated for many years.The relatively low enhancement factor and the poor uniformity of existing conventional or advanced nanoporous gold structures are still the main factors that limit their wide application as Raman enhancement substrates. Here, we report island-like nanoporous gold (INPG) fabricated by simply controlling the composition of the dealloying precursor.This nanostructure can generate ∼10 times higher enhancement factor (above 10) with ∼4 times lower gold consumption than conventional nanoporous gold. The dimensions of the gold islands can be controlled by the composition of the precursor. The enhancement factor can therefore be controlled by the gold island dimensions, which suggests an effective approach to fabricate better Raman enhancement substrates. Furthermore, INPG exhibits excellent Raman enhancement uniformity and reproducibility with the relative standard deviations of only 2.5% and 6.5%, which originate from the extremely homogeneous structure of INPG at both the microscale and macroscale. The excellent surface-enhanced Raman scattering properties make INPG a potential surface-enhanced Raman scattering substrate.
Plasmon-mediated
chemical reaction has a great potential to create
self-cleaning surface-enhanced Raman scattering (SERS) substrates.
However, few works have been reported to promote this goal. Here,
we report ultralow density nanoporous gold (ULDNPG) that possesses
an impressive full spectrum responsive characteristic with a reflectivity
lower than 5% in the waveband of 300–900 nm. ULDNPG was fabricated
by a sandwich dealloying strategy from ultradilute Au–Ag solid
solutions with the Au content as low as 1–5 at.%. The prepared
ULDNPG presents excellent SERS properties, including high sensitivity,
high uniformity, and reproducibility. The full spectrum responsive
characteristic of ULDNPG leads to an obvious plasmonic photocatalytic
activity. The short lifetime of the SP-excited hot carriers causes
a restricted self-cleaning SERS property and a strong photothermal
effect for ULDNPG structures.
The design and fabrication of surface-enhanced Raman scattering (SERS) substrates with high Raman enhancement, stability, homogeneity and processing compatibility is still one of the most challenging issues in SERS research.
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