Communication: Reactions and adsorption at the surface of silver nanoparticles probed by second harmonic generation

Abstract

Second harmonic generation from small gold metallic particles: From the dipolar to the quadrupolar response

The Effect of Composition, Morphology, and Susceptibility on Nonlinear Light Scattering from Metallic and Dielectric Nanoparticles

“…22,24 The absence of detectable SH intensity from MG/PS NPs for these two polarization combinations is expected for spherical particles, because p-in/s-out and s-in/s-out are forbidden. 25,26 Subsequently, we conclude that the SH intensity detected in pin/s-out and s-in/s-out from Ag NPs is because the shape of these NPs is not perfectly spherical. This result is in agreement with NLRGD calculations, 31 and we note that in the work by Russier-Antoine et al 39 the polarization-angle resolved measurement, not the AR-SHS measured with specific polarization configuration presented in this work, also revealed the deviation of the particle shape from a perfect sphere.…”

Adsorption of Anionic Thiols on Silver Nanoparticles

“…33,34 In earlier works, 25,26 our group has shown that adsorption and reaction of thiol molecules on the surface of metallic particles in colloidal solutions can be characterized by SHS. The SH signal detected in those experiments has been shown to be predominantly from the surface layer of atoms of the Ag nanoparticles.…”

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Figure S1) is known to contain two distinct contributions: A peak at 400 nm assignable to the SH signal and a much broader peak at longer wavelengths attributed to the two-photon excitation induced fluorescence (TPF). 25 The SH wavelength (400 nm) is in resonance with the localized surface plasmon (LSP) of Ag NPs in the size range used in this experiment and provides resonant enhancement for the SH signal. Similar to previous studies on neutral thiols, 25 As previously demonstrated, the adsorption of thiols on noble metal NPs can be characterized by the adsorption isotherm measured using SHS.…”

“…The experimental setup used in this work has been described previously. 25,26 Briefly, the fundamental light at a wavelength of ~800 nm was provided by a cell (1 cm pathlength) and stirred with a magnetic bar methods or continuously flown by a micropump producing a liquid-jet column of ~1 mm diameter. In both cases, the signal was collected within ~π/4 solid angle around the forward (fundamental beam propagation) direction.…”

Adsorption of Alkylthiol Self-Assembled Monolayers on Gold and the Effect of Substrate Roughness: A Comparative Study Using Scanning Tunneling Microscopy, Cyclic Voltammetry, Second-Harmonic Generation, and Sum-Frequency Generation

“…SHG. The short-time (few minutes) adsorption kinetics of a series of n-alkylthiols on polycrystalline gold was investigated in detail by SHG in the work of Dannenberger et al 58 More recently, Gan et al 59 used SHG to study the adsorption kinetics of ethanethiol, 1,2-benzenedithiol, and 3-mercaptopropanesulfonate on Ag nanoparticles. Here we used the SHG technique to probe the long-time (hours) adsorption of C16SH on gold in situ.…”