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Electro-optical sensor for the detection of extracellular ions
Bellan, Boris ; Salyk, Ota (referee) ; Vala, Martin (advisor)
The aim of this work was to prepare a platform based on electrochemical transistor that would allow both electrical and optical detection of ion exchange between the electrolyte and the layer of organic semiconductor. Semiconductor that have been used in this work was poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). The main goal was to verify whether the proposed platform meets the requirements of both characterization methods, and whether the sensitivity in the given arrangement is sufficient for the required range of analyte concentrations. The work also dealt with the study of the stability of the prepared platform in selected solvents and culture media, at the same time the method of optimizing the preparation of the photoresist foil and the completion of the OECT measuring cell was studied. A suitable solvent for polymethyl methacrylate was sought so that it did not affect the surrounding parts of the platform. Based on the obtained results, it was found that the selected photoresist for the preparation of the spacer frame is not suitable. However, it was found that the proposed platform satisfies both characterization methods. Therefore, it will be necessary to replace the current photoresist with a new, more chemically stable one.
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Real-time monitoring of cellular processes - current approaches
Švecová, Iva ; Hodný, Zdeněk (advisor) ; Groušl, Tomáš (referee)
This thesis aims to provide an overview of real-time live-cell imaging methods with a focus on the signalling pathways. The first, most thorough section is about fluorescence methods and is followed by sections about bioluminescence and label-free methods. In the fluorescence section, we will at first introduce the types of fluorophores and respective labelling approaches. Subsequently, we will go through the individual techniques, starting with single-fluorophore and FRET biosensors, continuing with kinetic modelling approaches, a FLIM method used to detect changes in the cellular environment, and ending with two methods used to improve the resolution. With each technique, we will shortly explain the working principle and look at the examples at which this method was used. Finally, we will look at the example of live-cell imaging of one signalling cascade.
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Methods for monitoring contamination in wastewater
Ravasová, Michaela ; Procházková, Michaela (referee) ; Vondra, Marek (advisor)
Bachelor thesis in the introduction explains the term wastewater. The basic indicators of wastewater pollution are presented and their significance and impact on water quality is explained. Afterwards are explained and described laboratory methods used to measure selected indicators of pollution. Since these methods are unsuitable for continuous wastewater monitoring, following section describes basic sensors for monitoring of wastewater directly at the measuring site. The basic principles which are used in sensors are described and parameters that sensors measure and their influence on environment is explained. Next, three chosen developing methods, i.e., biosensors, electronic noses and fluorescence spectroscopy, which will be applicable for on-line water monitoring in the future. The individual sensors are summarized in final tables. The aim of this work was to create simple overview of methods used for wastewater monitoring.
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Advanced simulations of photonic structures by FDTD method
Vozda, Vojtěch ; Veis, Martin (advisor)
Finite-Difference Time-Domain method (FDTD) is based on numerical solution of Maxwell's equations, nowadays widely used for simulating optical response of photonic structures. This paper provides brief introduction to the FDTD method and several important extensions which make the basic code much more versatile. In order to broaden analysis of photonic structures, transfer matrix method (TMM) is also involved. The code is firstly tested using simple model structures which optical response might be compared with different numerical or even analytical approaches. Debugged code is used to improve photonic crystals for enhanced sensitivity of biosensing devices based on refractive index changes of sensed medium. Last but not the least, properties (sensitivity and Q-factor of resonant peak) of holey waveguide are investigated in one-, two- and three-dimensional simulation. It is shown here, that even this simple structure may compete with complex photonic crystals in the field of biosensors. Powered by TCPDF (www.tcpdf.org)
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Microscopic study of multifunctional drug molecule adhesion to electronic biosensors coated with diamond and gold nanoparticles
Finsterle, T. ; Pilarčíková, I. ; Bláhová, I.A. ; Potocký, Štěpán ; Kromka, Alexander ; Ukraintsev, Egor ; Nepovimová, E. ; Musílek, K. ; Kuča, K. ; Rezek, B.
The easy and fast detection of drug content and concentration levels is demanded in biological research as well as in clinical practice. Here we study on microscopic level how nanodiamonds and gold nanoparticles interact with a multifunctional drug molecule directly on a biosensor surface. The sensors are made of interdigitated Au electrodes coated by 5 nm hydrogenated or oxidized nanodiamonds and further combined with Au colloidal nanoparticles (size 20 nm) providing nanoscale composite (spacing 100 nm). Atomic force microscopy is employed to measure local tip-surface adhesion forces and surface topography. AFM adhesion maps show that the drug binds to all types of nanoparticles and the adhesion is also significantly influenced by the substrates on which the nanoparticles are deposited. Role of local AFM tip interaction with nanostructured surface is also discussed.\n
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Study of possibilities of increasing the biocompatibility of organic semiconductor surfaces
Malečková, Romana ; Šafaříková, Eva (referee) ; Vala, Martin (advisor)
This bachelor thesis deals with the possibility of biocompatibilization of organic semiconducting polymer PEDOT:PSS using RGD peptide for the construction of biosensors. Samples were prepared and compared where the RGD peptide was bound directly, as well as samples with a peptide bound via crosslinker molecule sulfo-SANPAH. Whether the RGD peptide was bound to the substrate was determined by the method of measuring the contact angle of liquids with subsequent calculation of surface energy. The results were further verified by elemental analysis, infrared spectrometry and Raman spectroscopy.
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Pokročilé simulace fotonických struktur metodou FDTD
Vozda, Vojtěch ; Veis, Martin (advisor) ; Richter, Ivan (referee)
Finite-Difference Time-Domain method (FDTD) is based on numerical solution of Maxwell's equations, nowadays widely used for simulating optical response of photonic structures. This paper provides brief introduction to the FDTD method and several important extensions which make the basic code much more versatile. In order to broaden analysis of photonic structures, transfer matrix method (TMM) is also involved. The code is firstly tested using simple model structures which optical response might be compared with different numerical or even analytical approaches. Debugged code is used to improve photonic crystals for enhanced sensitivity of biosensing devices based on refractive index changes of sensed medium. Last but not the least, properties (sensitivity and Q-factor of resonant peak) of holey waveguide are investigated in one-, two- and three-dimensional simulation. It is shown here, that even this simple structure may compete with complex photonic crystals in the field of biosensors. Powered by TCPDF (www.tcpdf.org)
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Fabrication and application of graphene-metal heterostructure in biosensing by Surface Enhenced Raman Spectroscopy
Hegrová, Veronika ; Édes, Zoltán (referee) ; Konečný, Martin (advisor)
This thesis deals with fabrication of graphene/metal heterostructures and their application in biosensing by surface-enhanced Raman spectroscopy. The heterostructures are fabricated by selective deposition of gold colloidal nanoparticles onto silicon substrate, where the termination of both the gold colloidal solution and the silicon surface is controlled. Further, the assembled gold colloids are overlaid by graphene monolayer. The experiments have proved, that it is possible to observe the presence of biomolecules at very low concentrations if the parameters of graphene/metal heterostructures are well selected. The combination of both graphene and metal SERS properties have demonstrated their appropriateness for utilization in bisensing.
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Advanced simulations of photonic structures by FDTD method
Vozda, Vojtěch ; Veis, Martin (advisor)
Finite-Difference Time-Domain method (FDTD) is based on numerical solution of Maxwell's equations, nowadays widely used for simulating optical response of photonic structures. This paper provides brief introduction to the FDTD method and several important extensions which make the basic code much more versatile. In order to broaden analysis of photonic structures, transfer matrix method (TMM) is also involved. The code is firstly tested using simple model structures which optical response might be compared with different numerical or even analytical approaches. Debugged code is used to improve photonic crystals for enhanced sensitivity of biosensing devices based on refractive index changes of sensed medium. Last but not the least, properties (sensitivity and Q-factor of resonant peak) of holey waveguide are investigated in one-, two- and three-dimensional simulation. It is shown here, that even this simple structure may compete with complex photonic crystals in the field of biosensors. Powered by TCPDF (www.tcpdf.org)
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