New Era of Formulation as Silver Nanoparticles in Pharma

In various fields of science, nanoparticles of noble metals, particularly silver nanoparticles, have been widely used. Its specific properties, which can be integrated into the materials of biosensors, composite fabrics, cosmetics, antimicrobial applications, conducting materials, and electronic components, make it a very interesting topic to be studied in the fields of chemistry, biology, healthcare, electronics, and other related fields. Such unique features depending on the size, and shape of the silver nanoparticles. Various methods of preparation for the synthesis of silver nanoparticles have been reported, such as electron irradiation, laser ablation, chemical reduction and biological methods. Keywords: silver nanoparticles (AgNPs), particle size, localized surface plasmonic resonance (LSPR), characterization, application

Spectroscopic characteristics of colloidal solutions of metal nanoparticles

Nanoparticles are finding more and more practical applications in various fields of human activity, including veterinary and medicine. Due to the fact that the effectiveness of activity of colloidal solutions of nanoparticles is directly related to the state of aggregation of nanosized particles, it is urgent to use fast and convenient methods for assessing the physicochemical characteristics of such preparations. Nanoparticles have unique optical properties that depend on their size and shape. They can be determined by the refractive index of the light on the surface of the nanoparticles in a phenomenon known as plasmon resonance, which makes UV-Vis spectroscopy a valuable tool for studying and evaluating the characteristics of nanomaterials. Goal of the study is to study the optical characteristics of several samples of colloids of nanoparticles of noble metals (silver) and bioelements (copper, silicon dioxide) in order to determine the possibility of further application of UV-Vis spectroscopy for evaluation of activity and stability of colloidal solutions of nanoparticles. Commercial preparations based on nanoparticles of noble metals (silver) or bioelements (copper, silicon dioxide) in working dilutions recommended by manufacturers were used to study optical characteristics of the colloidal solutions. Optical density and absorption spectra were determined at the wavelengths (nm): 300-800 nm. The f plasmon surface resonance has been found in all test preparations, while all of them exhibited obvious nonlinear optical properties. The most pronounced plasma resonance peak is found in the colloidal solution of silver nanoparticles within a wavelength of 420 nm. In the case of a colloidal solution of copper nanoparticles, the peak of plasmon resonance was less pronounced and had a red shift (peak at 560 nm). In the colloidal solution of silicon silica, the plasmon resonance was less pronounced than other test preparations, being shifted to the blue side of the spectrum (360 nm).

Photochromic Core-Shell Nanoparticles

: The results of own spectral-kinetic studies in the field of nanophotochromism of the core‒shell type hybrid compounds are integrated. The properties of photochromic nanoparticles of this type based on photochromic spirocompounds (spiropyrans and spirooxazines), chromenes, and diarylethenes and nanoparticles of noble metals (Ag and Au), diamonds, graphene and its oxide, silica, fullerenes, and quantum dots are considered. Preparation methods of photochromic nanoparticles have been developed.

NANOPARTICLES OF NOBLE METALS ON THE SURFACE OF GRAPHENE FLAKES

Carbon is a spread element that has many different reaction combinations. Obtaining new composite materials based on nanoparticles is a very actual and perspective topic because nanoparticles possess unique properties. These properties are retained and even amplified when nanoparticles are located in various matrixes. Furthermore, nowadays, the creation of graphene-based composites and graphene-related structures is a promising area of synthesis of composite nanomaterials. Previous research has determined that graphene has a unique set of electrophysical, thermal, optical, and mechanical properties. In this study, the synthesis of nanocomposites representing nanoparticles of noble metals (Au, Pd, Rh) on the surface of graphene flakes were carried out, and the study of their composition, structure, physical and chemical properties, and possible applications in catalysis. The immobilization of nanoparticles on the surface of graphene oxide and graphene was developed, and the original method of synthesis of nanocomposite noble metal nanoparticles on the graphene flakes surface using supercritical isopropanol as a reduction agent for the transformation of graphene oxide into graphene was created. The study of physical and chemical properties of the obtained nanocomposites and results of the study of obtained nanocomposites as catalysts for model organic reactions of cross-coupling and hydroformylation showed that it is possible to create the graphene-based nanostructures as effective functional nanomaterials. Research on the synthesis of graphene compounds and its unique physical properties form a promising direction in the chemistry and physics of new inorganic functional materials. The resulting nanocomposites can be used in such branches as electrodes for LEDs and solar cells, field-effect transistors, supercapacitors, sensors, fuel cells.

New glass-based materials, activated by the nanoparticles of noble metals for applications in photonics and sensorics.

The paper considers properties of micron-sized regionsformed in the volume of oxide glasses with different content of silver oxide by direct laser writting. It has been shown the influence of the concentration of silver oxide, as well as parameters of laser irradiation on the size and luminescence intensity of the written microdomains.