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Electrical characteristics of graphene layers and their use as gas sensors
Kučera, Štěpán ; Kaspar, Pavel (referee) ; Macků, Robert (advisor)
This bachelor thesis focuses on the general characterization and description of graphene and related nanostructures. It involves production by the most used methods, including their advantages and disadvantages. Due to the impossibility of connection in the usual way, the graphene sample had to be contacted under visual inspection with a microscope with the tip contacts in the shielded area. Subsequently, it was subjected to current-voltage characterization with normal conditions on a Keithley 4200-CSC instrument. The next step was to measure the same sample under a different gas atmosphere. The result is a comparison of the specific responses to the change in gas atmosphere in which the graphene monolayer was exposed.
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Electrical characteristics of graphene layers and their use as gas sensors
Kučera, Štěpán ; Kaspar, Pavel (referee) ; Macků, Robert (advisor)
This bachelor thesis focuses on the general characterization and description of graphene and related nanostructures. It involves production by the most used methods, including their advantages and disadvantages. Due to the impossibility of connection in the usual way, the graphene sample had to be contacted under visual inspection with a microscope with the tip contacts in the shielded area. Subsequently, it was subjected to current-voltage characterization with normal conditions on a Keithley 4200-CSC instrument. The next step was to measure the same sample under a different gas atmosphere. The result is a comparison of the specific responses to the change in gas atmosphere in which the graphene monolayer was exposed.
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Novel fluorosensors based on naphthalimide derivatives
Garbárová, Veronika ; Dian, Juraj (advisor) ; Hraníček, Jakub (referee)
The aim of the diploma thesis was to prepare and characterize fluorescence sensor systems based on fluorophores and supramolecular components - cyclodextrins - attached to solid supports. In this work, functionalized 75 µm glass beads and two types of Nafion membranes were used as negatively charged solid surfaces. Derivatives of naphthalimide with a positively charged part allowing the attachment to surfaces were synthesized. The positively charged naphthalimide derivative was then attached on negatively charged surfaces via electrostatic interactions and the binding to the solid supports was examined using UV-VIS spectroscopy. Alternatively, the positively charged β-cyclodextrin derivative was also attached to the surface in an equimolar ratio with PNI-HEMPDA. The focus of the work were measurements of fluorescence sensor responses in the gas and liquid phase to linear alcohols - methanol to n-hexanol - for all sensor systems. For the studied sensor systems, the selected sensor parameters were determined - sensitivity, the limit of detection, linear dynamic range and a sensor response time constant. A practical application of the novel sensor system for the detection of ethanol in gasoline was examined. Fluorescence sensor response measurements of the prepared systems based on naphthalimide and...
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