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1.
Guralchuk GY Sorokin AV Katrunov IK Yefimova SL Lebedenko AN Malyukin YV Yarmoluk SM 《Journal of fluorescence》2007,17(4):370-376
Optical spectroscopy experiments were used to study the features of cyanine dye 3,3′-dimethyl-9-(2-thienyl)-thiacarbocyanine
iodide (L-21) aggregation in binary solutions DMF:Tris–HCl buffer (pH = 8) containing nucleic acids (DNA or RNA). The appearance
of absorption and luminescence bands associated with J-aggregates and dimers that are formed within the minor groove of DNA
has been observed. The model of L-21 J-aggregate structure is proposed. It has been found that dimers are the building blocks
of L-21 J-aggregates. Disorientation in dimers caused by the minor groove curvature is reason of observation of Davydov splitting
in absorption spectrum of L-21 J-aggregates. In the solution containing DNA the absorption and luminescence bands of L-21
J-aggregates exhibit the specific properties that allows the dye L-21 to be used as a fluorescent probe for DNA detection. 相似文献
2.
Lebedenko AN Guralchuk GY Sorokin AV Yefimova SL Malyukin YV 《The journal of physical chemistry. B》2006,110(36):17772-17775
Using fluorescent microscopy and microspectroscopy, optical properties and morphology transformations in individual pseudoisocyanine (PIC) J-aggregates in aqueous electrolyte solutions have been explored. A stringlike structure of J-aggregates with a string diameter much less than 1 microm has been observed. Photodestruction of the strings under short-wavelength excitation has been revealed. Rodlike PIC crystallites, about 1 microm in diameter, have been observed with time. The fluorescence spectrum of rodlike crystallites has been found to differ from that of stringlike J-aggregate and from PIC crystal powder spectra. The crystallites are very stable, and their photodestruction has not been observed under any excitation conditions. It has been found that rodlike crystallites in contrast to stringlike J-aggregates possess optical waveguide properties. The luminescence of crystallites can be observed only at the excitation spot and at butt ends located up to hundreds of micrometers from the excitation spot. 相似文献
3.
S. L. Yefimova G. Ya. Gural’chuk A. V. Sorokin Yu. V. Malyukin I. A. Borovoy A. S. Lubyanaya 《Journal of Applied Spectroscopy》2008,75(5):658-663
Interactions between the cationic polymethine dyes 3,3′-diethyloxacarbocyanaine iodide (DiOC2), 3,3′-dioctadecyloxacarbocyanine iodide (DiOC18), and 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) in the nano-scale volume of anionic sodium
dodecylsulfate (SDS) micelles have been studied using optical spectroscopy techniques. The solubilization of pairs of dye
molecules (DiOC18/DiI or DiOC2/DiI) within SDS micelles was monitored by Forster resonance energy transfer (FRET) between the dyes in each pair. The influence
of the hydrophobicity of the dyes DiOC2 and DiOC18 on the efficiency of their binding to SDS micelles and, consequently, on the efficiency of FRET between DiOC18 and DiI or DiOC2 and DiI fluorophors has been analyzed. It has been shown that hydrophobic interactions in addition to electrostatic interactions
are of key importance for the binding between the positively charged dyes and negatively charged surfactant micelles.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 646–652, September–October, 2008. 相似文献
4.
Svetlana L. Yefimova Irina Yu. Kurilchenko Tatyana N. Tkacheva Nataliya S. Kavok Igor N. Todor Nataliya Yu. Lukianova Vasyl F. Chekhun Yuriy V. Malyukin 《Journal of fluorescence》2014,24(2):403-409
We report the Förster resonance energy transfer (FRET)-labeling of liposomal vesicles as an effective approach to study in dynamics the interaction of liposomes with living cells of different types (rat hepatocytes, rat bone marrow, mouse fibroblast-like cells and human breast cancer cells) and cell organelles (hepatocyte nuclei). The in vitro experiments were performed using fluorescent microspectroscopic technique. Two fluorescent dyes (DiO as the energy donor and DiI as an acceptor) were preloaded in lipid bilayers of phosphatidylcholine liposomes that ensures the necessary distance between the dyes for effective FRET. The change in time of the donor and acceptor relative fluorescence intensities was used to visualize and trace the liposome-to-cell interaction. We show that FRET-labeling of liposome vesicles allows one to reveal the differences in efficiency and dynamics of these interactions, which are associated with composition, fluidity, and metabolic activity of cell plasma membranes. 相似文献
5.
K. O. Hubenko S. L. Yefimova T. N. Tkacheva P. O. Maksimchuk O. O. Sedyh O. G. Viagin A. V. Sorokin Yu. V. Malyukin 《Journal of fluorescence》2018,28(4):943-949
Studying the complexes of inorganic nanoparticles – organic dye molecules is of great importance for their theranostics application. In this paper, we report gadolinium-yttrium orthovanadate nanoparticles (VNPs) – Acridine Orange (AO) complex formation in water solutions. To study the interactions between VNPs and AO, the methods of steady-state and time-resolved spectroscopy were used. It was shown that in aqueous solutions containing VNPs, AO aggregation takes place with a sandwich-like stacking of AO molecules in the near-surface layer of VNPs. The VNPs–AO complex formation causes significant changes in the AO fluorescence spectrum, namely, the appearance of a new broad, structureless band in the long-wavelength spectral edge, which was not observed in AO spectrum in a pure water solution. By analyzing of the absorption, fluorescence excitation spectra and fluorescence decay, the static excimer origin of the long-wavelength fluorescence band has been established. 相似文献
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8.
A. S. Lebed S. L. Yefimova G. Ya. Guralchuk A. V. Sorokin I. A. Borovoy Yu. V. Malyukin 《Journal of Applied Spectroscopy》2010,77(2):183-188
The interaction of a series of cationic dialkyloxacarbocyanine perchlorate (DiOC
n
) dyes of different degrees of hydrophobicity with micelles of an anionic surfactant, sodium dodecylsulfate (SDS), has been
studied spectrophotometrically in aqueous solutions. The Benesi–Hildebrand equation was used to calculate binding constants
(K
b
) of the dyes to surfactant micelles, the fraction of dye bound to the micelles (f
mic
), and the standard free-energy change (ΔG
0) for the transfer of dye from the aqueous to micellar phase. It has been shown that the interaction of oppositely charged
dye molecules and surfactant micelles is controlled by both electrostatic and hydrophobic interactions. A small increase in
dye hydrophobicity due to lengthening of the hydrocarbon radical has been shown to cause an abrupt nonlinear increase of the
fmic value. This points to a key role of hydrophobic interactions in the binding of dye molecules with the micelles. 相似文献
9.
SL Mironov E Skorova G Taschenberger N Hartelt VO Nikolaev MJ Lohse S Kügler 《BMC neuroscience》2009,10(1):29-11
Background
cAMP is an ubiquitous second messenger mediating various neuronal functions, often as a consequence of increased intracellular Ca2+ levels. While imaging of calcium is commonly used in neuroscience applications, probing for cAMP levels has not yet been performed in living vertebrate neuronal tissue before. 相似文献10.
PF Hendrix SL Lachnicht MA Callaham X Zou 《Rapid communications in mass spectrometry : RCM》1999,13(13):1295-1299
Feeding strategies of earthworms and their influence on soil processes are often inferred from morphological, behavioral and physiological traits. We used (13)C and (15)N natural abundance in earthworms, soils and plants to explore patterns of resource utilization by different species of earthworms in three tropical ecosystems in Puerto Rico. In a high altitude dwarf forest, native earthworms Trigaster longissimus and Estherella sp. showed less (15)N enrichment ((15)N = 3-6 per thousand) than exotic Pontoscolex corethrurus ((15)N =7-9 per thousand) indicating different food sources or stronger isotopic discrimination by the latter. Conversely, in a lower altitude tabonuco forest, Estherella sp. and P. corethrurus overlapped completely in (15)N enrichment ((15)N = 6-9 per thousand), suggesting the potential for interspecific competition for N resources. A tabonuco forest converted to pasture contained only P. corethrurus which were less enriched in (15)N than those in the forest sites, but more highly enriched in (13)C suggesting assimilation of C from the predominant C(4) grass. These results support the utility of stable isotopes to delineate resource partitioning and potential competitive interactions among earthworm species. Copyright 1999 John Wiley & Sons, Ltd. 相似文献