Improve The Effective Resonance Light Scattering Of Three-Layered Plasmonic Au@Dielectric@Ag Bimetallic Nanoshells

The strong light scattering from SPR has received an extraordinary attention due to the useful applications in photodetectors, cell and biomedical imaging. However, the applications using light scattering require a high scattering cross-section along with low absorption losses near the resonance wavelength. In this paper, effective plasmonic scattering of three-layered Au-Ag bimetallic nanoshells with a dielectric separate layer has been studied using the quasi-static approximation of classical electrodynamics. Because of the surface plasmon resonance (SPR)-induced intense light absorption, the effective scattering intensity is much weaker than that of scattering cross section. However, the effective scattering intensity could be improved by tuning the geometric dimension and local dielectric environment of the nanostructure. It has been found that the greatest effective scattering takes place when the outer Ag nanoshell has a thick thickness or the dielectric separate layer has a small dielectric constant. The effective scattering also depends on the inner Au sphere radius and outer surrounding dielectric constant. Because of the mode transformation of the SPR, the effective scattering could also be greatly improved when the inner Au sphere has a very small or large size. However, the effective scattering intensity changes non-monotonously as the surrounding dielectric constant increases. The greatest effective scattering could be obtained when the surrounding dielectric constant has an intermediate value. This tunable effective plasmonic scattering of Au@Ag three-layered nanoshells presents a potential for design and fabrication of plasmonic optical nanodevice based on resonance light scattering.

Effects of the Mixing Protocol on the Self-Assembling Process of Water Soluble Porphyrins

The hierarchical self-assembling kinetics of the porphyrin 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (H2TPPS44−) into J-aggregates at high ionic strength under acidic conditions and eventually in the presence of an added chiral templating agent (tartrate) were investigated through UV/Vis spectroscopy, resonance light scattering, and circular dichroism (CD). The effect of changing the mixing order of the various components in the solution on the kinetic parameters and the expression of chirality on the final J-aggregates was evaluated. In this latter case, only when the chiral tartrate anion is premixed with the porphyrin, the resulting nano-architectures exhibit CD spectra that reflect the handedness of the chiral inducer. We discuss a general mechanistic scheme, with the involvement of ion pairs or dimers that offer an alternative pathway to the aggregation process.

Long-distance transfer of plasmonic hot electrons across the Au–Pt porous interface for the hydrogen evolution reaction

The hot electrons transfer from Au nanosphere to Pt interfaces is directly imaged by plasmon resonance light scattering microscopy. Remarkably, the hot electrons could persistently transfer across porous Au-Pt interfaces longer than 20 nm.

Two Novel Methods for the Determination of Benzalkonium Chloride in Bandages by Resonance Light Scattering Technology

In this study, two novel resonance light scattering (RLS) methods were developed for the determination of benzalkonium chloride. These methods were based on the formation of inorganic anionic-surfactant aggregates in a Clark-Lubs medium, which increases the resonance light scattering intensity of the reaction system and were also predominantly divided into sodium tungstate-benzalkonium chloride (method A) or phosphomolybdate-benzalkonium chloride (method B). The detection is performed both at 285 nm. Under the established conditions, the limits of quantification ranged from 0.10 mg L–1 to 1.00 mg L–1 with the R values of 0.9994 and from 0.20 mg · L–1 to 3.20 mg · L–1 with the R values of 0.9991, with good precision and accuracy both for method A and method B. The limits of detection were 0.029 mg · L–1 for method A and 0.013 mg · L–1 for method B. These two methods were successfully applied for the assay of benzalkonium chloride for the first time. All validation parameters were in agreement with the International Conference on Harmonization of Requirements for Registration Pharmaceuticals for Human Use (ICH) guidelines. Compared to the classical spectrophotometric method, these two methods take advantages of rapidity, high efficiency and good selectivity.