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This study was carried out to estimate the genetic diversity between cultivars of alfalfa using SRAP marker system (sequence-related amplified polymorphism). We tested 25 combinations of SRAP markers and revealed that seven of them were informative for DNA polymorphism identification. These combinations generated 129 PCR products with the percentage of polymorphic bands per pair ranging from 21 to 50%. Specific amplification products were identified for 14 cultivars for genetic certification.

We have obtained a new water-soluble form of boron(III) dipyrromethene luminophores using the example of 3,3',5,5'-tetraphenyl-ms-aza-2,2'-dipyrromethenate boron(III) (BODIPY) and Cremophor® (polyethylene glycol, PEG-40). The results of a study of the spectral-luminescent properties of the studied BODIPY–Cremophor®–aqueous–alcohol medium system are presented. It is found that Cremophor® is the only one of a series of investigated excipients (PEG-400, PEG-1000, polyvinylpyrrolidone, bovine serum albumin, sodium carboxymethylcellulose) providing solubilization of BODIPY in an aqueous medium, while maintaining its intense spectral characteristics, including fluorescence and luminophore, in the red region of the spectrum. The BODIPY–Cremophor® system is tested on two mouse cell lines: metastatic breast cancer and non-metastatic skin cancer. It is shown that the introduction of the BODIPY–Cremophor® system into both cell lines of mice leads to the detachment of cell cultures from the substrate and suppression of the development of cancerous tumors. The results obtained show that immobilization of BODIPY in PEG-40 in an aqueous-alcoholic medium makes it possible to obtain preparations with prolonged action, which can be used as photosensitizers (PSs) in photodynamic therapy and for bioimaging in cell biology.

The spectral luminescent and electrophysical properties of polymer films based on poly-N-vinylpyrrolidone with the stabilized derivatives of tetraphenylporphyrin in various aggregation states (monomers, J- and H-aggregates) were investigated. Films containing a monomolecular form of porphyrins are characterized by intensive fluorescence. For films with J-aggregates an electric response that was not practically observed in the case of H-aggregates was detected. The films obtained are also characterized by optical and electric response to pH change, particularly in the presence of ammonia and hydrogen chloride vapors. The obtained data allow polymeric films with immobilized porphyrins to be considered as potential material for the creation of film systems for sensor applications, photovoltaics, molecular electronics, and photocatalysis. The variability of the film synthesis methodology allows the aggregation state of the immobilized porphyrins to be changed directionally, which provides the possibility of obtaining films of hybrid organic materials with the desired photophysical properties.

New hybrid graphene and aluminum phthalocyanine structures are synthesized (graphene is prepared with the sonochemical method in N,N-dimethylformamide). The physicochemical properties of these hybrid systems are studied with transmission electron microscopy, Raman spectroscopy, and optical spectroscopy. We show that graphene in the system prevents the aggregation of aluminum phthalocyanine and leads to its stabilization in monomeric form. The results may be used to obtain new materials for various sciences and technologies.

The effect of the filler content on the optical absorption spectra, electroconductivity, and surface morphology of thin nanoocomposite films based on poly(n-xylylene)–tin (PPX–Sn) has been studied. The films under study are prepared in vacuum by cryochemical synthesis on polished quartz, glass-ceramics, and silicon substrates. After completing the preparation, the samples are exposed to air for some time prior to measurements. With an increase in the filler content, a nonmonotonic change in both surface morphology of films (by atomic force microscopy) and adsorption spectra is found. An analysis of the spectra shows that, at the filler concentration C ≤ 9 vol %, tin in the composite is in the oxidized form of SnO2, while at C = 12 vol % it is in a metal state, respectively. With an increase in C from 4 to 12 vol %, the increase in conductivity of nanocomposites is more than 7 decimal orders, with a sharp change in the region of C ≈ 9–12 vol %. The conductivity of the film consisting of nanoparticles (C = 100 vol %) is found to be low and comparable with that for composites with C = 4–5 vol %. With a decrease in the temperature from 300 to 15 K, the resistance of the sample with C = 12 vol % is found to decrease, while that for all other samples increases by the activation law. The activation energy with an increase in the filler concentration to 9 vol % is found to decrease, while that for the sample with C = 100 vol % increases by almost an order of magnitude. The most significant changes in the properties and morphology of the surface of nanocomposites are observed at a concentration of ~9 vol %, which apparently is the percolation threshold.

The spectral-fluorescent properties of various supramolecular systems based on chlorin e6 (Ce6) are determined to facilitate the development of new medicines for photodynamic therapy and diagnostics. The effect of various excipients, such as poly-N-vinylpyrrolidone (PVP), polyethylene glycol (PEG), bovine serum albumin (BSA), chitosan, Triton X-100 (TX-100), sodium hexametaphosphate (SHMP), and poly(dimethyldiallylammonium chloride) chloride (PDDAC), on the optical absorption and fluorescence of Ce6 is demonstrated. In the Ce6−PVP, Ce6−PEG, Ce6−BSA, Ce6−TX-100, Ce6−SHMP, and Ce6−PDDAC systems, Ce6 molecules are disaggregated and complexes thereof with excipients are formed. The quantum yield of Ce6 fluorescence in supramolecular systems is close to that of the free-form photosensitizer, in the absence of excipients. The results suggest that supramolecular complexes of Ce6 are promising for the development of medicines with controllable photodynamic activity.

A geometric approach to revealing the characteristic signs of photoresponse from semiconductor sensor materials is presented. It is shown by the example of zinc chalcogenides that natural decomposition of the transient photoresponse into geometrically ordered components is performed upon transforming their transient photoresponse into first-order and second-order signatures. Universal differential-geometric parameters and other indices, which are also applicable for other characteristics of semiconductor sensor materials, are applied for the system analysis of ordering the dynamic structure of the photoresponse.

It is shown that the photophysical properties of chlorophyll a (Chl) depend on the nature and relative amounts of 2-methyl-1,4-naphthoquinone (MNQ) and nicotinamide adenine dinucleotide phosphate (NADP). Photoinduced charge separation occurs in aqueous ethanol solutions of Chl (1 × 10−5 M) and NADP (5 × 10−6–5 × 10−4 M), resulting in the dynamic quenching of Chl fluorescence. Coordination interaction between Chl and NADP is established at an NADP concentration of ≥5 × 10−4 M. The nonlinear Stern-Volmer dependence in this range is due to the input from static quenching. It is shown that the quenching of Chl fluorescence in an MNQ solution at Chl and MNQ concentrations of 1 × 10−5 M and 6.7 × 10−5–1 × 10−4 M, respectively, is described by a linear dependence in the Stern-Volmer coordinates; no complex formation is observed for Chl and MNQ under these conditions, and electron transfer is of the dynamic type. Static or mixed-type energy transfer from MNQ to Chl dominates at elevated MNQ concentrations.

The optical absorption spectra of molybdenum disulfide prepared by monolayer dispersion of a crys- talline precursor in a liquid medium were studied. On the whole, the three-dimensional structure of the crystalline analogue was reconstructed in disperse MoS 2 dried to a powder state. A substantial fraction of the material trans- formed into a nanosized state during dispersion and was stabilized in the form of nanoparticles in various sol- vents. The stabilizing action of the solvents studied decreased in the series acetonitrile, ethanol > chloroform > water. The data on the optical absorption of MoS 2 suspensions in various solvents were evidence of a broad par- ticle-size distribution. Along with nanoscale particles, the samples contained larger particles responsible for long-wave absorption (>600 nm). The size of nanoparticles was estimated using an empirical correlation between the position of maximum A (the long-wave maximum of the first allowed absorption band) in the absorption spectrum and the size of particles ( 2 R ). This correlation was obtained using the literature data on monodisperse particles and mixtures of particles. The number of particles showed a tendency to increase as the concentration of disperse MoS 2 in acetonitrile decreased.

The dependence of electrical conductivity on the concentration of CdS (c) and temperature (T) over the temperature range 10–300 K was studied for poly-p-xylylene-CdS (PPX + CdS) nanocomposites prepared by solid-state cryochemical synthesis. The results were discussed in terms of the heterogeneous conductivity model including various charge transfer mechanisms in various nanocomposite regions. Under the illumination of a film with c > 11 vol % by a daylight lamp, the conductivity increased, and the σ(T) dependence was metallic in character at low temperatures. The photoconductivity of films at larger concentrations c was caused by the appearance of photoexcited electrons in CdS nanoparticles, the separation of charges at the nanoparticle-matrix boundary, and percolation effects in films. The PPX matrix was shown to actively participate in electrical conductivity; electrons in this matrix jumped between phenyl rings. The experimental dependence of dark conductivity σ(T) at temperatures from 150 to 300 K was analyzed using the Mott hopping conductivity model with variable jump lengths. The main points of the Mott theory of hopping conductivity were discussed.

Two-layer heterostructures with a high yield of charged current carriers were obtained and investigated. The heterostructures comprised monolayer dispersions of MoS2 in polyvinyl alcohol as the lower layer and the upper p-, n-, or bipolar transport layer (TL). It was found that dark conductivity of the two-layer heterostructures increased considerably compared with the conductivity of reference samples based on TL but containing no MoS2. After excitation from the TL side, maximum photoelectric sensitivity was obtained where TL long-wave absorption decreased and there was a high concentration of TL excited states at the interface that interacted with the surface of MoS2 particles. This interaction quenched the luminescence of TL transport centers and led to the photogeneration of both positively and negatively charged current carriers at the interface. Luminescence quenching could be of 50–60% at high MoS2 contents in the lower layer (90–100 wt %). This was evidence that the contact area of MoS2 particles with the polymeric transport layer exceeded the geometric interface dimensions and the interface had a relief surface (was fairly thick). It was found that the donor-acceptor properties of both MoS2 and the polymeric TL were very important for the photogeneration of charge carriers at the interface. When the MoS2 content in the lower layer was maximum, the effectiveness of the accumulation of minority carriers increased because of the formation of an alternative transport network associated with MoS2 particles. The conclusion was drawn that the photogeneration of charges at the interface resulted from the phototransfer of electrons between MoS2 particles and TL excited states.

For polyparaxylylene-CdS nanocomposite films prepared by solid-phase cryochemical synthesis, the dependences of the optical absorption spectra, photoluminescence intensity, and surface topography on the CdS concentration were examined. It was revealed that the most significant changes, such as the shift of the position of the exciton absorption band by ∼1 eV and the increase of the surface roughness (the magnitude of variation of heights h max − h min along a surface profile) occur within a CdS concentration range of from ∼5 to ∼8 vol %. The average size of the nanoparticles was determined from the position of the exciton absorption maximum: 2R np ≲ ≲ 3 nm at c ≤ 5 vol % and 2R np ≥ 5−7 nm at c ≥ 10 vol %. The formation of 3-nm particles at low CdS concentrations was confirmed by the existence of exciton photoluminescence with maximum at 370 nm. Exciton luminescence was not observed at c ≥ 10 vol %. By contrast, at all c values, photoluminescence with maxima at ∼520 and ∼570 nm, which is usually assigned to interstitial S and Cd atoms, correspondingly, and a the weak emission of unknown nature with a maximum at 545 nm were observed.

It was found that the specific features of the photodielectric response of CdTe crystals grown from the melt are determined by ensembles of macroscopic growth defects. The analysis of diagrams ɛ*(λ) and ɛ*(X), which characterize the dependences of the complex dielectric constant on the wavelength and coordinates, as graphic images of sequences of induced states of the crystal was carried out. It was demonstrated that such analysis allows for the identification of the ensembles of macroscopic defects, which are the sources of internal fields.

It was demonstrated that plots of the imaginary part vs. the real part of the complex dielectric constant ɛ*(λ) in relation to a wavelength for Cd1−xZnxTe crystals grown from the melt show a series of special features that were not observed in the plots for other II-VI compounds. These features were found to be related to a variety of growth defects and to the considerable influence of electric and elastic-stress fields produced by these defects on the dielectric properties of the crystals.

It is shown that acoustic treatment of piezoelectric zinc selenide crystals by exciting strong natural elastic vibrations can specifically alter their photoelectric and other properties. Irreversible changes in the stressed-strained state of the crystals under this treatment are responsible for characteristic features in the spectral dependences of the permittivity e′(λ) and the dielectric loss coefficient e′’(λ). These dependences plotted in the form of e*(λ) diagrams on the complex plane and also the spectrum of natural elastic vibrations can be used to monitor the treatment process.