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Synthesis and properties of tungsten tioxide layers fabricated by the sol-gel process
Hesková, Helena ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This work deals with the optimization of the preparation process of WO3 layers by the sol-gel method and their properties. Several precursor solutions were prepared which were applied to the substrate by spin-coating and drop-casting. The deposited layers were annealed at 450°C until complete degradation of the polymer matrix contained in the precursor. The structure of the layers was observed by scanning electron microscopy, their composition by the X-ray diffraction and their thickness was determined by profilometry. The properties of the prepared layers were also investigated by photoelectrochemical measurements.
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Biofunctionalization of water soluble CdTe quantum dots
Šibíková, Anna ; Drbohlavová, Jana (referee) ; Pekárková, Jana (advisor)
This bachelor thesis is focused on the research on biofuncionalization of water-soluble glutathione modified CdTe quantum dots (QDs). The thesis is divided into three parts. The first part is a theoretical introduction to the QDs and their synthesis, modifications and applications in biology together with an introduction to proteins and bioconjugation of QDs and BSA. In the second part I present the experimental results of water-soluble glutathione modified CdTe-GSH QDs preparation. The QDs were cleaned and bioconjugated with BSA at different concentrations. This is described in the third part of the thesis. I also discuss the obtained experimental results in the frames of available literature.
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Electrochemical detection of purine bases using thick film Cu2O electrodes
Gabriel, Petr ; Prášek, Jan (referee) ; Pekárková, Jana (advisor)
This work deals with the production process thick films electrodes. It is focused on the Cu2O working electrodes preparation by screen printing and spray coating - methods on the corundum substrate. In this work are described both methods of fabrication and basic electrochemical methods. Prepared Cu2O electrodes were used for electrochemical detection of purine bases (adenine, guanine) using cyclic voltammetry. The effect of pH on the detection of purines was also examines.
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Magnetic particles as analytical tool in medicine
Gablech, Evelína ; Pekárková, Jana (referee) ; Hubálek, Jaromír (advisor)
This work reports on knowledge of magnetic nanoparticles, modification of their surface and their using in different areas. Literature review describes using MNPs in separation techniques of analytic biochemistry to imobilizate nucleic acids and proteins. The matter of experimental part is synthesis of MNPs using coprecipitation of iron salts and next modification of their surface. In MNPs preparation the effect of the presence of PEG in the reaction mixture and the temperature effect on the resulting properties of MNPs was examined. MNPs surface was modified by two different methods, emulsion polymerization method with precursors MMA and AAc, and carboxylation method using 11 -mercaptoundecanoic acid. PEG or temperature had little effect on the properties of the prepared MNPs. Establishing carboxyl groups succeeded only when the method of emulsion polymerization was used.
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Investigation of titania dispergation by ball milling
Gregůrek, Martin ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This bachelor’s thesis deals with preparation of dispersed suspensions of titania suitable for material printing. The theoretical part deals with the properties of dispersions, methods of their preparation and capabilities analysis particle size of the dispersions. Experimental work has been focused on the study of the efficiency of milling depending on time. The particles were prepared by ball milling with glass balls in n-butanol of oscilating shaker LT2. Characteristics of the dispersions was evaluated on the device for measuring particle distribution Lasentec D600L by laser diffraction. The results were verified on the devices Zetasizer Nano ZS using dynamic light scattering and scanning electron microscope Carl Zeiss Ultra Plus.
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Switching of spin vortices in magnetic nanodiscs
Hladík, Lukáš ; Pekárková, Jana (referee) ; Urbánek, Michal (advisor)
The diploma thesis deals with the switching of spin vortices in magnetic nanodisks. First, the basic concepts of (micro)magnetism are defined and existing theoretical and experimental achievements in the field of switching of the two basic characteristics (chirality and polarity) of magnetic vortex are summarized. Then the principle of dynamic switching of magnetic vortex chirality using in-plane magnetic field pulse with a well defined amplitude and duration is presented. There is no need to use a certain shape of nanodisks or asymmetry in magnetic field distribution. Nanostructures were prepared by the multi-step electron beam lithography and ion beam sputtering. Individual steps of sample preparation and optimization for the magnetization dynamics measurements are described. Finally, the experimental measurements of the dynamic switching of chirality on prepared samples obtained by transmission x-ray microscopy at the synchrotron Advanced Light Source at Berkeley, USA are presented and discussed.
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Synthesis of quantum dots for proteins detection
Šibíková, Anna ; Fohlerová, Zdenka (referee) ; Pekárková, Jana (advisor)
This thesis is focused on synthesis of quantum dots (QDs) for protein detection. It comprises three parts. The first part summaries the theory of QDs, their synthesis, functionalization, interactions and applications in medicine. In the second part synthesis of CdTe/ZnS core/shell QDs modified by glutathione (GSH) is described, followed by the conjugation with biomolecules BSA and IgG. Several coupling agents such as EDC with NHS and CDI were used. In the last part, the final products were characterized by fluorescence spectroscopy and capillary electrophoresis. The results show the dependence of the fluorescence intensity of the QDs on pH range, concentration of BSA and IgG concentrations using different crosslinkers.
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Functionalization of gold nanoparticles for imaging
Jakubechová, Jana ; Pekárková, Jana (referee) ; Drbohlavová, Jana (advisor)
The diploma thesis deals with synthesis of gold nanoparticles and their surface functionalization suitable for in vitro imaging. In this view there are requirements for optical properties such as stability, monodispersity and no presence of cytotocxicity. In order to fulfill these demands the synthesis by Turkevich method with surface modification by glutathione and polytethylenglycol was performed. Analytical methods such as DLS, SEM and Zeta potential measurement were utilized to characterize the physical and chemical properties of synthesized gold nanoparticles. Finally, MTT assay was performed to evaluate toxicity of gold nanoparticles using HEK 293 cell line.
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Synthesis of quantum dots for in-vivo imaging
Ferdusová, Helena ; Majzlíková, Petra (referee) ; Pekárková, Jana (advisor)
The aim of this work was to synthesise water-soluble QDs using different precursors and stabilizers and to determine the toxicity of the synthesized QDs by in vivo imaging. Experiments were performed on water-soluble QDs (MPA-CdTe, MPA-CdTe/ZnS, MSA-CdTe, MSA-CdTe/ZnS, GSH-CdTe, GSH-CdTe/ZnS, TGA-CdTe, TGA-CdTe/ZnS, GSH-ZnSe and GSH-ZnSe/ZnS ) and toxicity was measured. Synthesized QDs were characterized by high intensity (fluorescence spectroscopy), FWHM and zeta potential (ZS Zetasizer) were selected due to their suitability for this task. The toxicity of QDs was determined by the MTT assay on the cell line HEK 293. The experiments show that a core/shell structure is less toxic than a core structure. The results indicate that the toxicity of our synthesized QDs is the lowest for MPA-CdTe (core structure) and MPA-CdTe/ZnS (core/shell structure).
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