Spectrochim Acta A Mol Biomol Spectrosc
December 2024
In this study, we have investigated the surface-enhanced Raman scattering (SERS) spectra of myoglobin on silver substrates with different morphology. The aim was to determine the optimal parameters of analyte and substrate preparation for obtaining of high-amplitude SERS spectra of proteins. It is shown that not only the morphology of the silver film, but also the method of analyte molecules deposition on the SERS substrate plays an important role.
View Article and Find Full Text PDFA stimuli-responsive (pH- and thermoresponsive) micelle-forming diblock copolymer, poly(1,2-butadiene)--poly(,-dimethylaminoethyl methacrylate) (PB--PDMAEMA), was used as a polymer template for the in situ synthesis of silver nanoparticles (AgNPs) through Ag complexation with PDMAEMA blocks, followed by the reduction of the bound Ag with sodium borohydride. A successful synthesis of the AgNPs on a PB--PDMAEMA micellar template was confirmed by means of UV-Vis spectroscopy and transmission electron microscopy, wherein the shape and size of the AgNPs were determined. A phase transition of the polymer matrix in the AgNPs/PB--PDMAEMA metallopolymer hybrids, which results from a collapse and aggregation of PDMAEMA blocks, was manifested by changes in the transmittance of their aqueous solutions as a function of temperature.
View Article and Find Full Text PDFIntegrated ring laser gyroscopes are perfect candidates for small-sized and high-performance gyroscopes. However, the performance of the ring laser gyroscope (RLG) near zero angular velocity is fundamentally restricted by the mode locking effect. In the paper the magneto-optical ring resonator is studied as a sensitive element of the integrated RLG.
View Article and Find Full Text PDFThe propagation of electromagnetic waves through a disordered layered system is considered in the paradigm of the homogenization of Maxwell's equations. Although the accuracy of the effective dielectric permittivity and/or magnetic permeability is still unclear outside the static approximation, we show that the effective wave vector can be correctly introduced even in high-frequency cases. It is demonstrated that both the real and imaginary parts of the effective wave vector are self-averaging quantities connected by the Kramers-Kronig relations.
View Article and Find Full Text PDFAnomalous optical properties of microscopically inhomogeneous dielectric films placed on a thick metal sublayer are investigated. We study the reflection, scattering, and absorption of the coherent electromagnetic radiation as a function of the incidence angle. Computer simulations show the existence of the incidence angle of the laser beam when the scattering and absorption increase simultaneously for the s-polarization so that almost 60% of the incident light goes in the scattering channel.
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