SERS Activity of Silver Nanosphere, Triangular Nanoplates, Hexagonal Nanoplates and Quasi-Spherical Nanoparticles: Effect of Shape and Morphology

Abstract

In this work, we prepared different morphologies of silver nanoparticles: nanosphere, triangular nanoplates, hexagonal nanoplates, and quasi-spherical shapes, through one-step synthesis. Hydrogen peroxide was used as the oxidizing agent during the reduction of silver nitrate by sodium borohydride, in the presence of tri-sodium citrate and poly-vinyl-pyrrolidone. The obtained silver nanoparticles were fully characterized by UV-Vis spectroscopy, Dynamic Light Scattering and Scanning Electron Microscopy, and successfully used as Surface Enhanced Raman Scattering (SERS) substrates. The effect of shape and morphology on the Raman scattering enhancement was evaluated by using methylene blue as target molecules. The Raman measurements demonstrated that the prepared substrates are reliable and sensitive with analytical enhancement factors, estimated to be around 105 with a concentration of methylene blue 1 μM. When triangular and hexagonal nanoplates were tested with different concentrations of analyte, they demonstrated a good linearity in Raman intensity with a good detection of methylene blue 0.1 μM.

The sensitive detection of methylene blue using silver nanodecahedra prepared through a photochemical route

“…11, the most intense peak in the SERS spectra can be observed at 1625 cm À1 , due to the enhancement of the Raman scattering, which is the main characteristic peak of MB. 64 This peak is assigned to C-C ring stretching and C-N ring stretching. 29 Raman spectroscopy can be used for quantifying the MB concentration and for calculating the limit of detection (LOD) of MB.…”

Detection of Ultra-Low Concentration of Methylene Blue by Porous Silicon Photonic Crystals Covered With Siver Nanoparticles as Efficient Sers Substrate

“…MB had Raman bands at ∼ 446 cm −1 and 1623 cm −1 that are attributed to the C-S-C skeletal deformation mode and C-C ring stretching, respectively. They are typical and most intense ones [21,[30][31][32][33][34][35]. The Raman spectra show a negligible weak signal at concentrations of 10 −11 M and below.…”

Tailoring Properties of Hafnium Nitride Thin Film via Reactive Gas-Timing RF Magnetron Sputtering for Surface Enhanced-Raman Scattering Substrates

“…Figure 7a shows Raman spectra of MB at a concentration of 10 −4 M on HfN thin films and a bare Si substrate. It can be seen that HfN thin films clearly showed Raman spectra with peaks at approximately 440, 768, 1180, 1394, and 1623 cm −1 , corresponding to the skeletal deformation of C-N-C, in-plane bending of C-H, stretching of C-N, asymmetrical stretching of C-N, and ring stretching of C-C, respectively [32]. The Raman intensity of MB molecules obtained from an HfN thin film substrate was five times higher than from a bare Si substrate.…”