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Materials with FR/NIR photoluminiscence
Chovanec, Filip ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This bachelor thesis is focused on issues of materials, whose fluorescence maximum is located in regions of the far-red (FR), which is in range from 700-800 nm or near-infrared (NIR), from 800-2500 nm, electromagnetic radiation. Materials, which this thesis is focused on, are organic molecules with charge transfer (CT) system. They are based on electron-donor and electron-acceptor groups located on the opposite sides of the same molecule. Diphenylamine behaves as electron-donor. This moiety is connected to different batch of atoms, which figure as electron-acceptor group. Connection is formed by -conjugated bridge of diphenyl stilbene or dixylil stilbene. Such a variable system has an optionally adjustable magnitude of charge transfer phenomenon, and it is reflected in the fluorescence maximum. Knowledge about fluorescence of these molecules, phenomena accompanying and outrunning this radiation, was acquired through the theoretical research. Strategies, how to set such a DA system or how to set up molecules with FR/NIR fluorescence were also obtained. Practically, characterization and dependence of fluorescence maximum on structure of these molecules, as well as dependence on solvent were determined by fluorescence spectroscopy. Photoluminescence quantum yield was calculated from emission and excitation spectra and studied how structural changes changed values of this quantum yield and fluorescence lifetime too. The result of the bachelor thesis was the finding, that the stronger the charge transfer phenomenon occurs in the molecule, the greater bathochromic shift of emission spectra was observed. At the same time, it was discovered that it was the case of liquid sample, solid samples had shown smaller bathochromic shift.
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Agregation of palmitoyl-modified hyaluronan
Lehocká, Nikola ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
This thesis deals with the aggregation behaviour of palmitoylhyaluronan in two degrees of substitution, namely 10 % and 16 %. Using a fluorescence spectroscopy method with pyrene as a fluorescence probe, we found a critical micellar concentration. The results were confirmed by measuring the dynamic light scattering, which also showed an increase in the size of aggre-gates with an increasing concentration. System stability is reduced by increased ionic strength as evidenced by zeta potential measurement. Experiments found that 16 % substitution sample can form a gel. The gel is very stiff and has excellent properties, which was confirmed by rhe-ology. We also managed to incorporate pyrene in the gel, which was demonstrated by the presence of highly solvated domains that could be polymer micelles. Based on these results, 16% substitution sample was subjected the MTT assay to cytotoxicity. The results confirmed that the examined sample was not toxic.
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Materials with FR/NIR photoluminiscence
Chovanec, Filip ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This bachelor thesis is focused on issues of materials, whose fluorescence maximum is located in regions of the far-red (FR), which is in range from 700-800 nm or near-infrared (NIR), from 800-2500 nm, electromagnetic radiation. Materials, which this thesis is focused on, are organic molecules with charge transfer (CT) system. They are based on electron-donor and electron-acceptor groups located on the opposite sides of the same molecule. Diphenylamine behaves as electron-donor. This moiety is connected to different batch of atoms, which figure as electron-acceptor group. Connection is formed by -conjugated bridge of diphenyl stilbene or dixylil stilbene. Such a variable system has an optionally adjustable magnitude of charge transfer phenomenon, and it is reflected in the fluorescence maximum. Knowledge about fluorescence of these molecules, phenomena accompanying and outrunning this radiation, was acquired through the theoretical research. Strategies, how to set such a DA system or how to set up molecules with FR/NIR fluorescence were also obtained. Practically, characterization and dependence of fluorescence maximum on structure of these molecules, as well as dependence on solvent were determined by fluorescence spectroscopy. Photoluminescence quantum yield was calculated from emission and excitation spectra and studied how structural changes changed values of this quantum yield and fluorescence lifetime too. The result of the bachelor thesis was the finding, that the stronger the charge transfer phenomenon occurs in the molecule, the greater bathochromic shift of emission spectra was observed. At the same time, it was discovered that it was the case of liquid sample, solid samples had shown smaller bathochromic shift.
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Assay of fluorescent products in erytrocytes of patients with Alzheimer' s disease
Kohutiar, Matej ; Wilhelm, Jiří (advisor)
Free radicals are highly reactive species with one unpaired electron in orbital. Reactive oxygen and nitrogen species count among important biologic molecules of radical nature. It is very important to fix a concentration of free radicals in cell on non-toxic limits. Products of radical damage are cumulated extra or intracellulary and they are main components of lipofuscin-like pigments. Lipofuscin-like pigments contains in their molecular structure fluorofores, so they are good substrates for fluorescent analysis. Alzheimer's disease is a very actual social and economical problem. Etiology of Alzheimer's disease is still unknown. Histologically, the characteristic presence of Alzheimer's disease is a senil plaques of amyloide ?. ROS and RNS diffuse through hematoencephalic barrier in vessel's lumen and attacks red blood cells. Radical damage of erythrocytes is associated with an increase of concentration of oxidative stress products in cytosol. Sample for fluorescent analysis has been prepared from a red-blood cell extract from 30 patients and 8 healthy controls. Fluorescent spectra of healthy controls have emission maxima in area 327-343nm. In compare with controls, spectra of pacients were more heterogenous in area upon 380nm. The study of oxidative cell damage is important for understanding of...
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Agregation of palmitoyl-modified hyaluronan
Lehocká, Nikola ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
This thesis deals with the aggregation behaviour of palmitoylhyaluronan in two degrees of substitution, namely 10 % and 16 %. Using a fluorescence spectroscopy method with pyrene as a fluorescence probe, we found a critical micellar concentration. The results were confirmed by measuring the dynamic light scattering, which also showed an increase in the size of aggre-gates with an increasing concentration. System stability is reduced by increased ionic strength as evidenced by zeta potential measurement. Experiments found that 16 % substitution sample can form a gel. The gel is very stiff and has excellent properties, which was confirmed by rhe-ology. We also managed to incorporate pyrene in the gel, which was demonstrated by the presence of highly solvated domains that could be polymer micelles. Based on these results, 16% substitution sample was subjected the MTT assay to cytotoxicity. The results confirmed that the examined sample was not toxic.
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Assay of fluorescent products in erytrocytes of patients with Alzheimer' s disease
Kohutiar, Matej ; Wilhelm, Jiří (advisor)
Free radicals are highly reactive species with one unpaired electron in orbital. Reactive oxygen and nitrogen species count among important biologic molecules of radical nature. It is very important to fix a concentration of free radicals in cell on non-toxic limits. Products of radical damage are cumulated extra or intracellulary and they are main components of lipofuscin-like pigments. Lipofuscin-like pigments contains in their molecular structure fluorofores, so they are good substrates for fluorescent analysis. Alzheimer's disease is a very actual social and economical problem. Etiology of Alzheimer's disease is still unknown. Histologically, the characteristic presence of Alzheimer's disease is a senil plaques of amyloide ?. ROS and RNS diffuse through hematoencephalic barrier in vessel's lumen and attacks red blood cells. Radical damage of erythrocytes is associated with an increase of concentration of oxidative stress products in cytosol. Sample for fluorescent analysis has been prepared from a red-blood cell extract from 30 patients and 8 healthy controls. Fluorescent spectra of healthy controls have emission maxima in area 327-343nm. In compare with controls, spectra of pacients were more heterogenous in area upon 380nm. The study of oxidative cell damage is important for understanding of...
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