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Characterization of 1-D Nanostructures by SPM Methods
Škoda, David ; Čech, Vladimír (referee) ; Pavlík, Jaroslav (referee) ; Dub, Petr (advisor)
The thesis is aimed at the characterization of carbon nanotubes and silver nanowires by Scanning Probe Microscopy, namely Scanning Tunneling Microscopy (STM), Atomic Force Microscopy (AFM), Conductive AFM (CAFM) and Scanning Near-Field Optical Microscopy (SNOM). Carbon nanotubes were analyzed by STM, AFM and CAFM microscopy. In a designed apparatus the silver nanowires were fabricated by template assisted deposition and were analyzed with respect to their geometry (AFM), local conductivity (CAFM) and optical properties (SNOM, microreflex spectroscopy). It was found that preferential type of carbon nanowires depends on the fabrication process. The measurements of local conductivity of the nanotubes revealed the similarity with the STM measurements. The AFM measurements of silver nanowires confirmed their growth inside the pores of polycarbonate template. Single nanowires exhibits the semiconducting behavior according to I--V measurement and localized plasmon resonances.
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The study of properties of anticancer drugs ellipticine, etoposide and doxorubicin in the forms of nanocarriers
Lengálová, Alžběta ; Stiborová, Marie (advisor) ; Martínková, Markéta (referee)
Currently available anticancer therapies are inadequate and spur demand for improved technologies. Among others, the utilization of nanocarriers for anticancer drug delivery has shown great potential in cancer treatment. Nanocarriers can improve the therapeutic efficiency of the drugs with minimization of the undesirable side effects. To evaluate potential application of this technology, two forms of nanocarriers have been studied: multi-walled carbon nanotubes (MWCNTs) and apoferritin. The aim of this study was to determine, whether given cytostatics (ellipticine, etoposide and doxorubicin) are bound to these nanotransporters and how are they released from them, especially depending on pH. Since the pH of the tumor cells is lower than the pH of healthy cells it would be preferred that the drugs would release from nanocarriers at the lower pH while at the physiological pH the release of the drug would be eliminated. The results found show that ellipticine is actually released from its MWCNT- and apoferrtin-encapsulated form at acidic pH (5.0), while at pH 7.4 its interaction with nanocarriers is stable. Ellipticine released from MWCNT is activated by microsomal enzymes to reactive metabolites (13- hydroxyellipticine and 12-hydroxyellipticine) forming DNA adducts. The results indicate that both...
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The study of properties of anticancer drugs ellipticine, etoposide and doxorubicin in the forms of nanocarriers
Lengálová, Alžběta
Currently available anticancer therapies are inadequate and spur demand for improved technologies. Among others, the utilization of nanocarriers for anticancer drug delivery has shown great potential in cancer treatment. Nanocarriers can improve the therapeutic efficiency of the drugs with minimization of the undesirable side effects. To evaluate potential application of this technology, two forms of nanocarriers have been studied: multi-walled carbon nanotubes (MWCNTs) and apoferritin. The aim of this study was to determine, whether given cytostatics (ellipticine, etoposide and doxorubicin) are bound to these nanotransporters and how are they released from them, especially depending on pH. Since the pH of the tumor cells is lower than the pH of healthy cells it would be preferred that the drugs would release from nanocarriers at the lower pH while at the physiological pH the release of the drug would be eliminated. The results found show that ellipticine is actually released from its MWCNT- and apoferrtin-encapsulated form at acidic pH (5.0), while at pH 7.4 its interaction with nanocarriers is stable. Ellipticine released from MWCNT is activated by microsomal enzymes to reactive metabolites (13- hydroxyellipticine and 12-hydroxyellipticine) forming DNA adducts. The results indicate that both...
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The study of properties of anticancer drugs ellipticine, etoposide and doxorubicin in the forms of nanocarriers
Lengálová, Alžběta
Currently available anticancer therapies are inadequate and spur demand for improved technologies. Among others, the utilization of nanocarriers for anticancer drug delivery has shown great potential in cancer treatment. Nanocarriers can improve the therapeutic efficiency of the drugs with minimization of the undesirable side effects. To evaluate potential application of this technology, two forms of nanocarriers have been studied: multi-walled carbon nanotubes (MWCNTs) and apoferritin. The aim of this study was to determine, whether given cytostatics (ellipticine, etoposide and doxorubicin) are bound to these nanotransporters and how are they released from them, especially depending on pH. Since the pH of the tumor cells is lower than the pH of healthy cells it would be preferred that the drugs would release from nanocarriers at the lower pH while at the physiological pH the release of the drug would be eliminated. The results found show that ellipticine is actually released from its MWCNT- and apoferrtin-encapsulated form at acidic pH (5.0), while at pH 7.4 its interaction with nanocarriers is stable. Ellipticine released from MWCNT is activated by microsomal enzymes to reactive metabolites (13- hydroxyellipticine and 12-hydroxyellipticine) forming DNA adducts. The results indicate that both...
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Self-sensing properties of alkali-activated slag composites under compressive loading
Míková, Maria ; Kusák, Ivo (referee) ; Rovnaník, Pavel (advisor)
Production of construction materials requires a large amount of energy. That can be decreased by using of waste materials. This thesis deals with the self-sensing properties of composites. It presents electrical properties of building materials and their measurement. In the experimental part, the influence of conductive fillers on the self-sensing properties of aluminosilicate composites was examined. Test cubes were made of alkali-activated slag with a content of graphite powder, carbon black, carbon fibers, steel fibers or carbon nanotubes. The fractional change in resistence during cyclic compressive loading was monitored.
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The study of properties of anticancer drugs ellipticine, etoposide and doxorubicin in the forms of nanocarriers
Lengálová, Alžběta ; Stiborová, Marie (advisor) ; Martínková, Markéta (referee)
Currently available anticancer therapies are inadequate and spur demand for improved technologies. Among others, the utilization of nanocarriers for anticancer drug delivery has shown great potential in cancer treatment. Nanocarriers can improve the therapeutic efficiency of the drugs with minimization of the undesirable side effects. To evaluate potential application of this technology, two forms of nanocarriers have been studied: multi-walled carbon nanotubes (MWCNTs) and apoferritin. The aim of this study was to determine, whether given cytostatics (ellipticine, etoposide and doxorubicin) are bound to these nanotransporters and how are they released from them, especially depending on pH. Since the pH of the tumor cells is lower than the pH of healthy cells it would be preferred that the drugs would release from nanocarriers at the lower pH while at the physiological pH the release of the drug would be eliminated. The results found show that ellipticine is actually released from its MWCNT- and apoferrtin-encapsulated form at acidic pH (5.0), while at pH 7.4 its interaction with nanocarriers is stable. Ellipticine released from MWCNT is activated by microsomal enzymes to reactive metabolites (13- hydroxyellipticine and 12-hydroxyellipticine) forming DNA adducts. The results indicate that both...
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Chemorezistive gas sensor
Venkrbec, Lukáš ; Pytlíček, Zdeněk (referee) ; Prášek, Jan (advisor)
This thesis deals with the detection of gases. Based on the research, the theoretical part is devoted to the principles and construction of chemical gas sensors, especially the chemoresistive gas sensors, mainly with the active layer consisting of metal oxides and carbon nanotubes. In the second half of the theoretical part the carbon nanostructures, their properties and the methodology of preparation are reviewed. The experimental part deals with the type of support structure, preparation of the active layer and the method of its deposition and he principle of detection. In the results and discussion, the thesis focuses on the detailed processing of the results and the evaluation of the response ammonia, the impact of the modifications and procedures. In the end, the results obtained are compared, both with each other and with the relevant literature.
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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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Gas sensor based on carbon nanoparticles
Morávek, Petr ; Pytlíček, Zdeněk (referee) ; Prášek, Jan (advisor)
This thesis deals with characterization of gas sensors based on carbon nanomaterials. In the theoretical chapter, the basic terms connected with the gas detection field, properties of different carbon nanoparticles and methods of their preparation are described. Practical experiments include the evaluation of samples` responses to ammonia, influence of annealing on their response and comparison of pure samples and their modifications.
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Modification of electrochemical sensors working electrodes for biological substances detection
Weiss, Vojtěch ; Prášek, Jan (referee) ; Majzlíková, Petra (advisor)
The aim of this work is modification of working electrode surface of screen-printed electrochemical sensors using carbon nanotubes. General knowledge about sensors, their categorization, thick-film technology, properties, preparation and utilization of carbon nanotubes and selected electrochemical methods are reported in theoretical part. Three different methods of working electrodes modification with carbon nanotubes are described in the experimental part of the thesis. Furthermore characterization of modified and unmodified electrodes using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy is presented. All results are summarized and discussed in the conclusion of this work.
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