Luminescent analysis etching processes of sapphire with gold nanocrystals in electronbeam

The presented work considers the possibility of studying the processes of radiation-induced ki-netics restructuring of the sapphire surface with gold nanocrystals using the time dependence intensity of cathodoluminescence spectra. It was shown that the main of color centers in the UV region of the spectrum of cathodoluminescence of sapphire are F+centers, and the F-band is suppressed. The study of the time dependence of the intensity of F+centers confirms the ab-sence of the surface melting stage of sapphire during irradiation with a beam of electrons with an accelerating voltage of 50 keV. The small line widening value Cr3+ corresponds to minor temperature devi-ations on the sapphire surface during electronic irradiation. A qualitative model describing etching of sapphire sur-face with gold nanocrystals during electron action is proposed. The model considered is based on radiation-induced Auger decay of sapphire and formation of intermetallic phases in the process of the exothermic reaction in the Au-Al sys-tem

Application of Luminescent Microscopy in Analysis of Anatomic-diagnostic Signs of Fruits of Sea Buckthorn

Introduction. Sea buckthorn (Hippophae rhamnoides), the family Eleagnaceae – a promising source of biologically active substances, the traditional raw materials of which are fruits. The existing regulatory documentation (ND) lacks such an indicator of the authenticity and good quality of the fruit as «microscopy». Despite the available data on the anatomy and histology of the fruits of this type of medicinal plant material (MPM), the scientific literature does not describe the luminescence features of the tissues of sea buckthorn fruit. It is known that the luminescent features of tissues make it possible to identify the localization of biologically active structures, and also, in some cases, to conduct selective diagnosis of MPM.Aim. The aim of this work was to study the characteristics of the luminescence of the tissues of dried crushed fruits of sea buckthorn, and also to optimize the conditions for analysis.Materials and methods. The object of the study was the dried, crushed fruits of sea buckthorn of various species. The study of microdiagnostic signs was carried out according to the State Pharmacopoeia of the XIV RF GPA.1.5.3.0003.15 «Technique of microscopic and microchemical studies of medicinal plant materials and herbal medicines». A stereomicroscopic study was carried out on a Biomed-6 microscope. The luminescence of sea buckthorn fruit tissues was examined using a luminescent microscope of the Micromed-3 Lum brand.Results and discussion. The most pronounced yellow glow is observed for the tissue of the pulp and epidermis of the fetus, which is associated with the highest content of fatty oil in these structures. Groups of phenolic compounds contained along with oil give a greenish tint to objects, while condensed tannins give a brownish tint. The plates that make up the corymbose hairs do not exhibit bright luminescence; a weak glow is characteristic of the joints of the hair platelets. The walls of stellate hairs have a faint greenish glow. Fragments of the actual fruit («sac») are brownish in color, without their own luminescence, as well as the seed peel. The embryo has its own greenish luminescence due to the presence of both a fatty oil and a complex of storage substances.Conclusion. The luminescent analysis of sea buckthorn fruits was carried out for the first time. The choice of a method for preparing the studied MPM for microscopic examination is experimentally substantiated. The luminescent analysis revealed the peculiarities of the glow of the tissues of the fruits of sea buckthorn. The main microdiagnostic signs of crushed dried sea buckthorn fruits and their biometric characteristics are specified. The analysis of the obtained data will allow us to further develop the section «Microscopic signs» for inclusion in the PA project on MPM, widely cultivated and used by the domestic pharmaceutical industry for the production of herbal medicines.

A Novel Double Core-Shell Bionanoparticle Formed by Ferritin and Baculoviral Polyhedrin

In this study, we got a step forward of the baculoviral polyhedrin (Polh) exploitation as a new nanobiomaterial. We recruited human H-chain ferritin (FTH) as scaffold and Gaussia luciferase (hGluc) as luminescent signal molecule, preparation, characterization and luminescent analysis of the bionanoparticles formed by the fusion proteins of them mentioned above inspire us to present a view that baculoviral polyhedrin is a nanobrick to be a new nanobiomaterial. The bionanoparticle that formed by FTH and Polh fusion protein is a novel double core–shell structure. The properties of baculoviral polyhedrin make itself a promising new nanobiomaterial for application in bionanotechnology.

Baltic amber inspection: micro-macro-structural and luminescent analysis

The solution of the problem of amber (succinite) flaw detection by microscopic analysis and luminescent analysis of amber macrostructure is proposed. The proposed method allows to obtain a rapid analysis of the defective state of the material structure. Given the growing demand for the use of such materials on an industrial scale and the insufficiency of existing methods, the proposed method may be a new solution to the problem of flaw detection. The basis of the proposed method for studying the macro structure of amber is transmission spectroscopy, luminescent analysis method. Samples of raw, heat-treated and pressed amber of the Palmniken Deposit obtained in the city of Kaliningrad of the Russian Federation were used as objects of research. Samples of different degrees of transparency and heat treatment were selected. It is established that the distinctive luminescence intensity at the defect boundaries is a characteristic of the presence of internal defects of the material and indicates the location of internal fractures, microcracks and other mechanical damage. The proposed method may be of interest in the theory of knowledge of materials science, research related to the processes of flaw detection of organic materials.

Energy transfer in liquid and solid nanoobjects: application in luminescent analysis

Radiationless resonance electronic excitation energy transfer (ET) is a fundamental physical phenomenon in luminescence spectroscopy playing an important role in natural processes, especially in photosynthesis and biochemistry. Besides, it is widely used in photooptics, optoelectronics, and protein chemistry, coordination chemistry of transition metals and lanthanides as well as in luminescent analysis. ET involves the transfer of electronic energy from a donor (D) (molecules or particles) which is initially excited, to an acceptor (A) at the ground state to emit it later. Fluorescence or phosphorescence of the acceptor that occurs during ET is known as sensitized. There do many kinds of ET exist but in all cases along with other factors the rate and efficiency of ET in common solvents depends to a large extent on the distance between the donor and the acceptor. This dependency greatly limits the efficiency of ET and, correspondingly, does not allow the determination of analytes in highly diluted (10–9–10–15 M) solutions. To solve the problem of distance-effect, the effects of concentrating and bring close together the donor and acceptor in surfactant micelles (liquid nanosystems) or sorption on solid nanoparticles are used. Various approaches to promote the efficiency of ET for improvement determination selectivity and sensitivity using liquid and solid nanoobjects is reviewed and analyzed.