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Using Voltammetric Method for Monitoring of Antioxidant Content in Biofuels
Tomášková, M. ; Chýlková, J. ; Navrátil, Tomáš ; Šelešovská, R.
The simple and fast method for analysis of Propyl gallate (PG) in biofuels was proposed in this paper. Voltammograms of antioxidant under study were recorded using linear sweep voltammetry method at a gold disc electrode in supporting electrolyte containing 0.18 mol L-1 H2SO4 and 10 % ethanol. For purposes to monitor effects on fuel quality caused by oxidative degradation, the proposed method was applied to samples of biodiesel and Ekodiesel® (the blend of biodiesel with fuel diesel). The analysis of PG can be performed without pretreatment of Ekodiesel samples, and after extraction using distilled water in case of biodiesel samples.
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Study of 2-Nitrofluorene Interaction with DNA at a Glassy Carbon Electrode
Skalová, Štěpánka ; Stávková, K. ; Vyskočil, V. ; Barek, J.
2-Nitrofluorene (2-NF) is a nitrated polycyclic aromatic hydrocarbon (NPAH) which occurs as the environmental pollutant. It is a potential carcinogen and mutagen. Interaction of deoxyribonucleic acid (DNA) with 2-NF was monitored using an electrochemical DNA biosensor prepared from a glassy carbon electrode (GCE) and low-molecular-weight DNA by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and square-wave voltammetry (SWV).\nThere were no damaging interactions observed between DNA and 2-NF using EIS. However, CV shows intercalation of this substance into the DNA structure to form the complex 2-NF–DNA. Intercalation was also observed by SWV, confirming intercalation to reduce the number of electroactive sites and thus reducing the peak heights of adenosine and guanosine.
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Electrochemical sensor for ascorbic acid detection
Hlavička, Michal ; Kynclová, Hana (referee) ; Majzlíková, Petra (advisor)
This work deals with electrochemical detection of ascorbic acid using screen-printed three-electrode sensors. The work is divided into three parts, where the first describes the theory of thick-film technology, including the types and compositions of the pastes, fabrication and firing. The second part deals with the methods, measurement principles and the electrochemical detection of ascorbic acid. Experiments were done using screen-printed carbon electrodes in a solution of phosphate buffer and ascorbic acid. In conclusion the results are evaluated.
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Nonplatinum catalysts for polymer exchange membrane fuel cells
Talába, Michal ; Chladil, Ladislav (referee) ; Novák, Vítězslav (advisor)
This work brings a study about non-platinum catalysts, alkaline membranes and methods that interprets catalytic activity. Work deals with a research on non-platinum catalysts based on MnO2 with addition of support substances, measuring of their properties using cyclic voltammetry and hydrodynamics theory. Also a fuel cell measurement of catalytic materials on PVA membrane is executed. The outcome of this work is evaluation of voltammetry and fuel cell measurements. The results of all methods are compared too.
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Spray-coated working electrodes of electrochemical sensors
Lechner, Filip ; Majzlíková, Petra (referee) ; Prášek, Jan (advisor)
This thesis is about the selection of the better type of thick film working electrode for the detection of substances in aqueous solutions, modified by spray coated carbon nanotubes. The theoretical part of this thesis describes the technology of thick film, properties and production of carbon nanotubes, introduction to electrochemistry and electroanalytical methods for the detection of substances in aqueous solutions. The practical part is aimed to realization of the working electrodes by thick film technology and their modification by spray-coated layer consist of carbon nanotubes. Electrodes are characterized using voltammetric methods, electrochemical impedance spectroscopy and electron microscopy. In conclusions is selected the most suitable type of working electrodes for reproducible electrochemical analysis.
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Study of DNA-doxorubicine interaction by electrochemical methods on nanostructured electrodes
Přibyl, Jakub ; Fohlerová, Zdenka (referee) ; Kynclová, Hana (advisor)
Cancer diseases are one of the leading causes of mortality worldwide, for this reason, great attention anticancer drugs. Doxorubicin falls into the category of the most widely used cancer drugs. The method of electrochemical impedance spectroscopy were investigated properties of golds electrodes without deposit nanoparticles and electrodes with deposit gold nanoparticles. Using voltammetric measurements we detected doxorubicin and investigated the interaction of doxorubicin with oligonucleotides on gold electrodes without nanoparticles and electrodes modified with gold nanoparticles.
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