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Electrochemical properties of selected psychoactive compounds
Jiroušková, Eliška ; Sokolová, Romana (advisor) ; Fischer, Jan (referee)
This Diploma Thesis focuses on the electrochemistry and spectroelectrochemistry of three new psychoactive substances (NPS). These compounds are easily accessible on the market and they are not regulated by current legislation. Due to the huge amount of these drugs it is difficult to identify them in human organism. Three representatives of new psychoactive substances were studied: two stimulants (3-fluorophenmetrazine, 3-FPM and 4-methylpentedrone, 4-MPD) and one of the fentanyl derivatives (FMAcF, m-fluoro methoxyaceyl fentanyl). Drugs often undergo oxidation or reduction during biotransformation in human organism therefore the electrochemical behaviour was studied. The main goal of this work was to determine the initial intermediates of redox processes, clarify reaction scheme (including electron transfer coupled with chemical reaction) and suggest the redox mechanism. The electrochemical properties were studied using cyclic voltammetry with a glassy carbon electrode as a working electrode. The compounds 3-FPM and FMAcF were oxidized within the available potential window and 4-MPD was both reduced and oxidized. The reaction scheme of all compounds was found to be ECE. UV/Vis spectroelectrochemistry revealed the formation of reaction intermediates. Infrared spectroelectrochemistry and...
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The design of electrochemical sensor with integrated potentiostat chip
Uhlár, Martin ; Novotný, Marek (referee) ; Adámek, Martin (advisor)
The research on electrochemical sensor applications in combination with application-defined electronic circuits is a very fast developing field of modern sensorics. Device designing of unique integrated systems with specific properties and parameters is now becoming the everyday practice for producers of devices based on the latest technology progress in microelectronics. In the process of realization of a new device type, the main objective consists in increasing the possibility of detecting very low concentrations of heavy metals in the given chemical solution, extending the signal-to-noise ratio, and measuring the potential of a sensor. The general aim of this Master’s thesis is to design the topology of a sensor based on the thick film technology, to materialize the sensor, and to make experimental measurement using the sensor prototype. The practical reason for basing the measurement on the application of this thick film sensor is to find out whether the operational integration of the sensor and the circuit has been achieved according to the original hypothesis. Importantly, it is also necessary to determine whether the reproducibility of measured results has been reached. The innovative aspect of the created device consists in the improvement of output characteristics given by the integration of ASIC (IMAM CHIP). The integration of ASIC on the surface of the sensor eliminates the huge parasitic influence that affects the accuracy of measurement.
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Biomarker detection using electrochemical method with microfluidic chip
Klepáčová, Ivana ; Svoboda, Ondřej (referee) ; Neužil, Pavel (advisor)
The thesis is focused on the development of the electrochemical system with microfluidic platform for the detection of multiple biomarkers. It analyses the use of biomarkers for the early diagnosis of cancer. The theoretical part contains basic information about voltammetric methods and microfluidic systems. The practical part provides solutions to the microfluidic chips, including the description of the used materials, designs, methodologies of preparation and conclusions from the testing of the manufactured microfluidic systems. The thesis describes the lock-in electrochemical system which measures the response of 4 electrochemical cells simultaneously. For the electrochemical system measurements, an electrochemical chip consisting of 64 electrochemical cells was used. The results of the analysis include the processing of the system tests and detected voltammetric curves of the Fe2+/Fe3+ solution and cysteine.
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Effect of temperature on electrochemical parameters of Li-S battery
Bečan, Jan ; Skala, Kateřina (referee) ; Jaššo, Kamil (advisor)
This bachelor's thesis deals with the production of lithium-sulfur battery and the effect of changing temperatures on its electrochemical parameters. The theoretical part is focused on primary and secondary batteries and their historical evolution, anode and cathode materials for lithium-ion batteries and next-generation batteries. The practical part is focused on preparing the electrode material for lithium-sulfur battery, completion of electrochemical cell and measuring the values of cycling charge/discharge at different temperatures.
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Catalysts for positive electrode of hydrogen-oxygen fuel cell
Kováč, Martin ; Bača, Petr (referee) ; Novák, Vítězslav (advisor)
Master's thesis deals with new methods of preparing catalytic materials for positive electrode of an oxygen-hydrogen fuel cell and the influence of potassium permanganate or doping agent molar mass change on theirs attributes. Further it studies the use of proper measuring methods designed to qualify theirs attributes and the presentation of achieved results. In particular methods of linear sweep and cyclic voltammetry and the processing of data using Koutecky-Levich and Tafel plot and wave log analysis. Values of half-wave and onset potential and kinetic coefficient have been measured and calculated.
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Electrodeposition of thin tantalum layers from ionic liquids and measurement of their electrical properties
Svobodová, Ivana ; Boušek, Jaroslav (referee) ; Šimůnková, Helena (advisor)
The thesis is focused on the electrodeposition of tantalum from ionic solution 1-butyl-1- methylpyrrolidinium bis(trifluoromethylsulfonyl) imide, ([BMP]Tf2N) at 200°C and description of related transfer and kinetic phenomena on the interface between the ionic solution and working electrode. Furthermore, the electrodeposition of tantalum layers in different ionic solutions containing tantalum salts and especially in ([BMP]Tf2N) is introduced. In the last part of the thesis, results of cyclic voltammetry, surface analysis SEM and elemental analysis EDX are discussed. MIS (metal-insulator-semiconductor) structure was determined comprising porous anodic alumina as the insulator and semiconductive TaxOy on the top of the insulator. The electric conductivity of the MIS structures was studied by using amper-volt IV and CV characteristics. The results of the cyclic voltametry, impedance spectroscopy and chronoamperometry are discussed.
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Investigation of intercalation of alkaline metals in electrochromic devices
Kortyš, Petr ; Špičák, Petr (referee) ; Svoboda, Vít (advisor)
This work deals with investigation of intercalation of alkaline metals in electrochromic devices by the help of the quartz crystal microbalance method. The general aim is to investigate the influence of molar mass and resistance on properties of vanadium pentoxide and tungsten trioxide electrochromic films. The main measuring method used for investigating of interacalation of sodium and lithium ions into these films is the cyclic voltammetry. Drawn graphs reveals that sodium and lithium ions shows different qualities during intercalation, particularly in participation of solvent, therefore, in the influence of molar mass and in structural changes in the films.
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Electrochemical Characterization of Nanostructured Surfaces Modified by Substancies with Thiol Bound
Urbánková, Kateřina ; Kynclová, Hana (referee) ; Hrdý, Radim (advisor)
This master thesis deals with nanotechnology, nanoparticles and nanostructured surfaces, electrochemical methods, especially voltammetry, cyclic voltammetry, electrochemical impedance spectroscopy and contact angle measurement. One part is focused on electrodes primarily nanostructured and modified by substancies with thiol bound. Tutorial for preparation of gold nanostructured electrods is introduced in practical section including SEM photos of electrode surface. Nanostructured and bare gold electrodes were modified by 11-mercaptoundecanoic acid, streptavidin, glycine and biotin and measured by cyclic voltammetry, electrochemical impedance spectroscopy and contact angle.
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