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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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New technique on a chip for rapid detection of biological materials
Pejović Simeunović, Jelena ; Foret,, František (referee) ; Táborský,, Petr (referee) ; Hubálek, Jaromír (advisor)
Tato práce navrhuje techniku separace a detekce na čipu pro kvantové tečky (QD, „quantum dots“) konjugované s různými proteiny, za účelem sledování vlivu vazebného činidla na potlačení intenzity uorescence QD způsobené konjugací s proteinem a za účelem provedení multianalytické imunoanalýzy k identifikaci malých množství daného proteinu. Za optimálních podmínek byly biokonjugované QD úspěšně odděleny od těch nezkonjugovaných během 10 minut. Částice a cílové roztoky byly smíchány a detekce na čipu byla provedena za pomoci zařízení vyvinutého v naší laboratoři. Byl použit pouze jeden zdroj excitačního světla v kombinaci s několika filtry pro různé emisní vlnové délky. Fluorescence emitovaná dvěma typy konjugovaných QD mohla být poté zaznamenána současně, protože QD emitovaly světlo na různých vlnových délkách, ačkoliv byly excitovány při stejné vlnové délce. Smícháním dvou typů QD biokonjugovaných se dvěma druhy proteinů a protilátek jsme dokázali detekovat imunokomplexní píky s různými plochami. Plocha pod píkem závisela na koncentraci QD a antigenů, na postupu reakcí protilátka–antigen a ukázalo se, že je lineárně korelována s koncentrací antigenu. Ukázali jsme, že kapilární elektroforéza QD na čipu může být použita jako citlivá technika pro detekci biologických molekul. Hlavními výhodami této metody jsou jednoduchost, malé požadavky na objem vzorku i činidla a také vysoká účinnost separace.
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Plasmon enhanced photoluminescence
Édes, Zoltán ; Kůsová,, Kateřina (referee) ; Šikola, Tomáš (advisor)
Diplomová práce se zabývá fotoluminiscencí polovodičových materiálů zesílené plazmonovými polaritony. Je popsána základní teorie interakce mezi lokalizovanými povrchovými plazmonovými polaritony a fotoluminiscenčními látkami. Dva mechanismy, které mohou vést k fotoluminiscenci zesílené plazmonovými polaritony jsou diskutovány. Následně je popsán návrh aparatury pro měření fotoluminiscence a způsob její realizace. Funkčnost aparatury je ověřena měřením fotoluminiscenčních spekter objemového GaN, nanokrystalického Si a CdTe kvantových teček. Nakonec je zkoumána metoda přípravy vzorků sestávajících z kovových nanokuliček a fotoluminiscenčně aktívních CdTe kvantových teček.
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Strong coupling in plasmonic antennas
Beneš, Adam ; Křápek, Vlastimil (referee) ; Kejík, Lukáš (advisor)
Localized surface plasmons generated by ilumination of metallic nanostructures focuses light into nanoscale regions where it can interacts with other nanoobjects nearby. This bachelor's thesis focuses on fabrication of plasmonic antennas suitable for strong coupling with non-conductive or semiconductor nanostructures such as dye molecules or quantum dots in visible range. At first we put forward some theoretical background and summary of strong coupling systems. In the main section we describe process of fabrication and characterization of plasmonics antennas as well as deposition methods for emitors. Lastly, we study interactions in our systems using spectroscopic measurements and strong coupling is realized using FDTD simulations.
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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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Use of fluorescence methods for the study of protein interactions
Johaníková, Klára ; Bezděková,, Jaroslava (referee) ; Pavelicová, Kristýna (advisor)
The diploma thesis "Use of fluorescence methods for the study of protein interactions" is focused on the use of fluorescence methods for the study of protein interactions using electromigration methods and Förster resonance energy transfer (FRET). The aim of this work was to create a bioconjugate of metallothionein (MT) protein with quantum dots (QDs) and commercial dyes. FRET was subsequently studied between these conjugates. QDs were synthesized under UV light and conjugation with MT was performed via a carbodiimide zerolengthcrooss-linker (EDC / sulfo-NHS), which serves to activate carboxyl groups and allows bioconjugation of the ligand by covalent bonding. Due to the high proportion of cysteines in MT, this protein has a very high affinity for metals. It is also involved in scavenging free radicals and there are studies that show that MT is overexpressed in cancer cells. Attention was also paid to the study of MT dimerization, which leads to an understanding of oxidative dimerization of MT and thus can contribute to understanding the formation of free radicals in the body and to deepen the knowledge about neurodegenerative disorders such as Parkinson's or Alzheimer's disease or amyotrophic lateral sclerosis. The formation of the MT dimer was confirmed by energy transfer between the donor (QDs) and the acceptor (commercial dye-cyanine) through the physical phenomenon of FRET and MALDI-TOF-MS.
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Biosensors based on modified nanoparticles
Mihajlović, Ana ; Majzlíková, Petra (referee) ; Hubálek, Jaromír (advisor)
This thesis deals with biosensors based on modified semiconductor quantum dots(AIIBIII). This work is divided into three main parts. The first deals with the theory necessary for the use of QDs in bioapplications, there are described methods of synthesis, application and bioconjugation of QDs . In the practical part, GSH-CdTe, CdTe-MPA and TGA-CdTe quantum dots were prepared by direct colloidal synthesis. These quantum dots were then modified by EDC in order to increase affinity to BSA (bovine serumalbumin). For the analysis of samples were used Infinite M200,Tecan and HORIBA Jobin Yvon FluoroLog detector Quanta . The third part is the summary of results and work achievements.
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GRAPHENE APPLICATION IN ELECTRONICS AND TECHNOLOGY OF PREPARATION
Zahradníček, Radim ; Sofer,, Zdeněk (referee) ; Macák, Jan (referee) ; Hubálek, Jaromír (advisor)
This thesis focuses on the study of graphene application in electronics and technology of preparation. In addition to the basic properties of graphene, the theoretical part of the work also describes the methods of its preparation, transmission, characterization and possibilities of application in electronics. The experimental part is divided into three chapters. The first chapter deals with the production of graphene by deposition from the gaseous phase, its transmission and application in the field of solar cells. The Poly(methyl methacrylate) polymer was first used for transfer of graphene, which was later replaced by Rosin due to less contamination of graphene at the end of the transmission process. The second chapter deals with the preparation of quantum dots by exfoliation in the liquid phase from graphite and its application in voltammetry. Voltammetry was utilized in this work to detect hydrogen peroxide using a gold electrode modified by quantum dots from graphene and other dichalcogens (MoS2, MoSe2, WS2, WSe2). In the last chapter, the influence of the substrate and the deposition conditions of graphene is studied by means of a plasma-reinforced phase-out of gas to growth, while the prepared graphene was characterized by imaging and spectroscopic methods. The entire experimental growth of graphene was managed and evaluated using a planned experiment.
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Preparation of nanostructures using nanoporous template
Dzuro, Matej ; Hrdý, Radim (referee) ; Drbohlavová, Jana (advisor)
The aim of the work described in this paper is to prepare electrochemically an optical sensor consisting of TiO2 quantum dots (QDs) using nanoporous Al2O3 template in the first step and to modify the surface of QDs with gold layer by evaporation process, again using nanoporous template, in the second step. This easy, cheap and rapid approach provides homogenous and highly ordered distribution of both nanostructures on substrate. The final objective is to characterize the physical parameters and fluorescent properties of TiO2/Au sensor designed for optical detection of biomolecules such as DNA and proteins.
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Synthesis of core/shell quantum dots for diagnostics
Mihajlović, Ana ; Vaculovičová, Markéta (referee) ; Pekárková, Jana (advisor)
This thesis deals with biosensors based on modified semiconductor core/shell quantum dots (QDs) for diagnosis. The work is divided into four main parts. The first one discusses the theory required for the use of QDs in bioaplications, there are described methods of synthesis, modification, application and bioconjugation of QDs. In the experimental part, CdTe/ZnS QDs with core/shell structure were prepared, in which the core was modified by MPA, GSH and TGA. In the next step, these QDs were further modified using CDI, EDC and NHS as mediators in order to increase affinity to BSA (bovine serum albumine) and IgG (imunoglobuline G). Prepared conjugates were characterized by fluorescence spectroscopy (Infinite M200Pro, Tecan) and capillary electrophoresis (Agilent 7100).
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