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Electrochemical biosensor for the study of DNA methylation
Petrula, Jakub ; Hrdý, Radim (referee) ; Hynek, David (advisor)
This bachelor’s thesis deals with design and optimalisation of custom biosensor for detection of methylated DNA. Teoretical part explains the mechanism and importance of DNA methylation. Next section describes analytical methods used in connection with DNA methylation and some basic direct and indirect methods of detection. Final part is dedicated to experiment itself, which is divided into several sections. Section one deals witch modification of working electrode and optimalisation of detection method. Second section introduces two different ways of DNA methylation detection. First is based on direct detection and second one on detection through the biosensor. Final part shows determination of methylcytosine from sample based on analysing characteristic attributes of signal and numeric algorithm based on curve fitting.
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Characterization of working electrodes of electrochemical sensors modified by carbon nanomaterials
Vančík, Silvester ; Majzlíková, Petra (referee) ; Prášek, Jan (advisor)
This bachelor thesis deals with electrochemical detection of substances using screen-printed electrochemical sensors. The theoretical part describes thick film technology, sensors, selected parts of electrochemistry, voltammetry and carbon nanomaterials. The practical part includes the modification of standard screen-printed electrode by oxygen plasma and spray-coated carbon nanomaterials and its experimental comparison using cyclic voltammetry and scanning electron microscopy. The measured values were processed and evaluated numerically and graphically. In comparison with standard working electrode, the current responses of both electrodes were improved significantly.
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Advanced techniques of micro- and nanosystems fabrication for sensors
Márik, Marian ; Pekárek, Jan (referee) ; Hubálek, Jaromír (advisor)
The use of micro- and nanotechnologies is necessary in the development of advanced sensor systems. In this thesis few selected technologies were studied and tested on fabrication of creating two different systems for bioelectrical and electrochemical applications. For biolelectrical applications a chip with a pair of gold nanoelectrodes was designed and implemented. For electrochemical analysis a novel two electrode system was designed and realized, which should contribute by greater sensitivity and accuracy in amperometric detection compared with three-electrode systems in voltammetric analysis. The fabricated systems were tested and the results were discussed.
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Electrochemical biosensor for glucose detection
Matula, Tomáš ; Majzlíková, Petra (referee) ; Prášek, Jan (advisor)
This thesis pays attention to electrochemical sensors for the detection of glucose. The theoretical part deals with the technology of thick film, their application and firing. It is further described electrochemistry, electrodes used in electrochemistry and analytical methods based on electrochemical reaction. End of theoretical part deals with electrochemical biosensors for detection glucose using special electrodes based on enzyme glucose oxidase. In the experimental part is processed amperometric measure for detection glucose using screenprinted sensors S10 and S8 with immobilized enzyme glucose oxidase. Next was studied effect of plasma, dissolved potassium chloride, storage, ascorbic acid and the reproducibility of the sensors.
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Characterization of electronic properties of nanowires for electrochemistry
Kovařík, Martin ; Čech, Vladimír (referee) ; Kolíbal, Miroslav (advisor)
Elektrochemické metody nacházejí využití v mnoha aplikacích (např. senzorice, skladování el. energie nebo katalýze). Jejich nespornou výhodou je nízká finanční náročnost na přístrojové vybavení. Abychom lépe porozuměli procesům probíhajícím na elektrodách, je dobré znát elektronickou pásovou strukturu materiálu elektrody. Úkolem této práce je vyhodnotit výstupní práci a pozici hrany valenčního pásu nových materiálů pro elektrody, konkrétně cínem dopovaného oxidu india pokrytého nanotrubicemi sulfidu wolframičitého. Ultrafialová fotoelektronová spektroskopie a Kelvinova silová mikroskopie jsou metody použité pro tuto analýzu. Zvláštní důraz je kladen na přípravu vzorků elektrod pro měření, aby nedošlo k nesprávné interpretaci výsledků vlivem vnějších efektů jako je např. kontaminace nebo modifikace povrchu.
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Advanced plasmonic materials for metasurfaces and photochemistry
Ligmajer, Filip ; Vala,, Milan (referee) ; Bauch, Martin (referee) ; Šikola, Tomáš (advisor)
Plazmonika, tedy vědní obor zabývající se interakcí světla s kovovými materiály, nabízí ve spojení s nanotechnologiemi nezvyklé možnosti, jak světlo ovládat a využívat. Výsledkem tohoto spojení může být například zaostřování světla pod difrakční limit, zesilování emise nebo absorbce kvantových zářičů, či extrémně citlivá detekce molekul. Tato práce se zabývá zejména možnostmi využití plazmoniky pro vývoj plošných optických prvků, tzv. metapovrchů, a pro fotokatalytické aplikace založené na plazmonicky generovaných elektronech s vysokou energií, tzv. horkých elektronech. Nejprve jsou vysvětleny teoretické základy plazmoniky a je poskytnut přehled jejích nejvýznamnějších aplikací. Poté jsou představeny tři studie zabývající se využitím plazmonických nanostruktur pro ovládání fáze a polarizace světla, pro vytváření dynamicky laditelných metapovrchů, a pro foto-elektrochemii s horkými elektrony. Společným prvkem těchto studií je pak používání pokročilých, resp. v rámci těchto oblastí netradičních, materiálů, jako např. oxidu vanadičitého nebo dichalkogenidů přechodných kovů.
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Preparation Techniques and Characterization of Electrodes with Nanostructured Surface
Hrdý, Radim ; Trnková, Libuše (referee) ; Janderka,, Pavel (referee) ; Hubálek, Jaromír (advisor)
Nowadays, nanostructures fixed on solid substrates and colloidal nanoparticles permeate through all areas of human life, in area of sensors and detection as well. This dissertation thesis deals with the fabrication of nanostructures on the surface of planar electrodes via self-ordered nanoporous template of aluminum trioxide. The nanofabrication, as one of many possible techniques, is used to increase the active surface area of electrodes by creating unique surface types with specific properties. These electrodes are very perspective in the applications, such as biomolecules electrochemical detection and measurement. The transformation of aluminum layer into non-conductive nanoporous template in the process of anodic oxidation is a fundamental technique employed to obtain the array of nanostructures in this thesis. The fabrication of high quality nanoporous membranes with narrow pore size distribution on various types of metallic multilayers is one of the key experimental parts in this work. Several problems associated with the production of the thin-film systems, including the dissolving the barrier oxide layer, are discussed and solved. Another part of this work deals with the use of nanoporous membrane as a template for the production of metallic nanostructures via electrochemical metal ions deposition directly into the pores. The obtained nanostructures as nanowires, nanorods or nanodots are characterized by the scanning electron microscopy and energy-dispersive or wavelength X-ray spectroscopy. The electrode surface, modified by gold nanostructures suitable for the detection of biomolecules, has been chosen for the electrochemical measurements, due to the gold biocompatibility. The nanostructured electrodes were characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The effect of nanostructured surface geometrical parameters, including the size of the electrochemically active area, on the results of electrochemical measurements has been observed and compared to flat gold electrodes. Two model biomolecules, namely guanine and glutathione, have been chosen for the study of potential application of these nanostructures in biosensors.
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Study of MnOx properties using RRDE
Podal, Pavel ; Vondrák, Jiří (referee) ; Novák, Vítězslav (advisor)
This master thesis deals with qualifications of the catalytic materials for positive electrode low-temperature fuel cells. The teoretical part focuses on the physical and chemical properties of low-temperature fuel cells. There are described methods of hydrodynamic RDE and RRDE. RRDE study utilizes methods linear and cyclic voltammetry for qualifying performance of catalytic materials and presentation of results. The practical part describes the preparation various types of carbon materials. There are monitored the oxygen reduction using RRDE. Catalytic materials are evaluated: CV, stability, kinetic parameters, creation of intermediate H2O2 and kinetics of electrode reactions.
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The lead detection in solders
Macháň, Ladislav ; Prášek, Jan (referee) ; Adámek, Martin (advisor)
This work deals with issues of lead detection in solder irons used in electrotechnics. The general aim is to study principles of quantitative heavy metal detection by the electrochemical methods, optimal method selection and construction of detecting instrument.
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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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