Gold Nanoparticles Deposited on a Conical Anodic Aluminum Oxide Substrate for Improved Surface-Enhanced Raman Scattering

Abstract

In this study, a highly ordered gold nanoparticle (AuNP) monomer array based on a gold-coated conical anodic aluminum oxide (AAO) template was fabricated to produce a ring-shaped hot line between the gold layer and AuNPs instead of the existing hot spot between the metal nanoparticles. The surface-enhanced Raman scattering signal of the synthesized nanostructured template was 80 times higher than that of a flat gold surface and 3.7 times higher than that of ordered AuNP monomers arranged by the conical AAO template. The template was also fabricated based on a wet chemistry process, which allows for considerably easier and quicker production of large-area templates. KEYWORDS: surface-enhanced raman scattering (SERS), Raman spectroscopy, finite-difference time-domain (FDTD) method, anodic aluminum oxide (AAO) template, gold nanoparticles, plasmonic nanoparticle

Tuning plasmonic properties by promoting the inward Hg diffusion via oxygen plasma treatment in gold nanorods coated with a mesoporous silica shell

“…[1][2][3][4][5][6][7] Among those, an-isotropic plasmonic nanoparticles such as gold nanoparticles (AuNPs) have been widely used for Hg detection and purification by probing the change in the optical properties of AuNPs due to their strong interaction with Hg. [8][9][10][11][12] The strong affinity between Au and Hg forms nanoscale amalgams when the AuNPs are exposed to Hg ions. Dark-field (DF) microscopy and spectroscopy have been used to investigate the localized surface plasmon resonance (LSPR) spectral change due to Au-Hg interactions in the amalgamation process at the single-particle level.…”

“…1–7 Among those, anisotropic plasmonic nanoparticles such as gold nanoparticles (AuNPs) have been widely used for Hg detection and purification by probing the change in the optical properties of AuNPs due to their strong interaction with Hg. 8–12…”

Ordered Anodic Aluminum Oxide-Based Nanostructures for Surface-Enhanced Raman Scattering: A Review

“…It is interesting that a high density of hot spots was observed between the Au nanodots, as well as an abundant ring-shaped hot line between the Au film layers and the Au nanodots, which significantly improved the SERS signals. 107 With the development of SERS technology, it is challenging for SERS substrates to obtain adequate hot spots. In addition to narrowing the gaps between nanodot arrays, tuning the substrate morphology and composition is a favorable approach to realize the coupling of multistage plasma effects.…”

“…In order to solve the above problems, Lee and his team fabricated Au nanoparticle-aligned and gold-coated nanostructures by precisely anchoring Au nanoparticles in conical nanopores of AAO templates obtained through six-times anodization, as shown in Figure d. It is interesting that a high density of hot spots was observed between the Au nanodots, as well as an abundant ring-shaped hot line between the Au film layers and the Au nanodots, which significantly improved the SERS signals …”

“…(d) Schematic of the fabrication and SEM images of Au nanoparticles-arrayed gold-filmed AAO nanostructure. Adapted with permission from ref . Copyright 2021, American Chemical Society.…”