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Biosensors based on functionalized graphene
Pavlásková, Lucie ; Skládal, Petr (referee) ; Bartošík, Miroslav (advisor)
V této práci byl demonstrován grafenový polem řízený transistor (GFET) jako platforma pro detekci glukózy. Sukcinimidyl ester pyrenbutanové kyseliny (PSE) sloužící jako nosič a enzym glukóza oxidáza (GOx) byly úspěšně použity k funkcionalizaci grafenového kanálu ve FE transistoru. Enzym GOx byl imobilizován na kanálu pro glukózovou detekci, jelikož indukuje selektivní katalytickou reakci glukózy. Proces funkcionalizace byl charakterizován pomocí Ramanovy spektroskopie a Atomární silové mikroskopie (AFM). Vyrobený biosenzor na bázi grafenu umožnil elektrickou detekci glukózy ve dvou různých uspořádáních. V uspořádní FET prostřednictvím posunu Diracova bodu ve voltampérové charakteristice, jakož i v nastavení pro kotinuální monitorování v reálném čase prostřednictvím změny odporu grafenového kanálu. Tato studie naznačuje, že grafen je slibným materiálem pro vývoj nanoelektronických biosenzorů včetně aplikací pro monitorování hladiny glukózy.
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Carbon sorbents for biologically active substances
Lanžhotská, Aneta ; Sedláček, Petr (referee) ; Pekař, Miloslav (advisor)
This Bachelor thesis deals with the general characteristics of lignite and its definitions as a material system. Lignite represents geologically the youngest type of coal, and belongs to kaustobiolites, which are masses with varying degrees of carbonification of the original phytomass. The degree of carbonification is roughly between peat and brown coal. Particular attention was paid to the application of lignite as a cheaper and more versatile sorbent to replace activated carbon and for the use of sorption of biologically active substances in biotechnology. The specific structure and composition give the lignite the natural sorption capability. In model experiments, polyphenols were used as significant microbial inhibitors for which lignite had a high sorption and for glucose, which lignite practically did not absorb. A model experiment was carried out with a hydrolyzate of a corn biomass, where the lignite showed optimal sorption.
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Production and characterization of mead produced by different technologies
Kilian, David ; Vítová, Eva (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis is focused on the technology of producing mead from the chosen kind of honey with a variety of sugar concentrations with the use of modern producing technological procedures with the cold and hot process. The theoretical part is focused on the history of mead and its technological development. It focuses, in detail, on modern large scale technologies – both cold and also the hot process. In the practical part of the thesis, the production of samples of mead with various sugar concentrations from three kinds of honey with the use of two technological processes (hot and cold process) was conducted firstly. Secondly, the characteristics of the samples were conducted from the view of the volume of HMF – Hydroxymethylfurfural, ethanol, glucose, fructose, the chosen organic acids and elements with sensory analysis. The prepared samples were compared and discussed concerning differences to find out the differences of the use of the two manufacturing technologies (cold and hot process), the chosen kinds of honey and the influence of sugar before the fermentation on the final product.
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Double-gate biosensor of glucose based on functionalized graphene
Malatinová, Michaela ; Pavlásková, Lucie (referee) ; Bartošík, Miroslav (advisor)
V tejto bakalárskej práci bola skúmaná funkcionalizácia grafénu s sukcinimidyl ester pyrenbutanovou kyselinou a enzýmom glukóza oxidáza pre detekciu glukózy biosenzorom. Funkcionalizovaný grafén bol implementovaný ako kanál v poľom riadenom tranzistore pre výrobu biodetekčného zariadenia. Proces funkcionalizácie potvrdila Ramanova spektroskopia a mikroskopia atomárných síl. Charakterizácia senzoru a jeho kvalít bola sledovaná pomocou transferových kriviek a časovej odozvy senzoru. Posun Diracovho bodu a jeho poloha boli analyzované v závislosti na rôznych koncentráciach glukózy s ohľadom na efektivitu funkcionalizácie. Výber hradlovej elektródy v grafénovom poľom riadenom tranzistore bol skúmaný vzhľadom na jeho možný dopad na výsledky merania.
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Effect of glucose on the corrosion behaviour of AZ31 magnesium alloy in saline solution
Faltýnková, Denisa ; Hasoňová, Michaela (referee) ; Doskočil, Leoš (advisor)
This bachelor thesis deals with the influence of glucose concentration on corrosion behaviour of magnesium alloy AZ31 in saline solution. The theoretical part briefly summarises the use of magnesium and its alloys in biomedical applications and offers insight into the current state of knowledge of the effect of glucose on corrosion of these materials. In the experimental part, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to evaluate the electrochemical behaviour of AZ31 alloy in saline solution with varying concentrations of glucose. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterise post-corrosion surface of the alloy. The corrosion environment was analysed by measurement of conductivity, pH, inductively coupled plasma atomic emission spectroscopy (ICP-OES) and liquid chromatography with conductivity detector. Results showed that glucose, depending on concentration, impairs corrosion resistance of AZ31 alloy in 0.9% NaCl. Three organic acids were identified in the corrosion environment, of which gluconic acid is the most abundant.
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Chromatographic determination of simple sugars in selected beverages
Jurečková, Zuzana ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
An important part of the drinks are simple carbohydrates, because this thesis focuses on this issue. The theoretical part describes the characteristics , production , metabolism and the use of simple carbohydrates such as glucose, fructose and sucrose. There is also the definition of drinks and their main divisions . The literature review is based on the experimental part of analyzing selected beverages by high performance liquid chromatography with refractometric detection coupled to columns or alkyl ion-exchange phases. In conclusion, the results were compared to determine and comment . Nowadays the emphasis is on the correct functioning of the digestive tract. An important factor that supports the intestinal microflora is a prebiotic carbohydrate - tagatosa This could become tagatosa whose properties , production, metabolism in the body and any use is also included in the search . In the experimental part is listed possible optimization analysis of samples containing tagatosy on both types of columns in the HPLC system. The result is again commented in conclusion.
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Non-invasive Blood Glucose Measuring
Vítová, Hana ; Chmelař, Milan (referee) ; Sekora, Jiří (advisor)
Goal of my master´s thesis is examination of non-invasive blood glucose measurement methods, and designing of device for non-invasive blood glucose reading. The introductory chapter of thesis contains description of know different methods for blood glucose measurement, mainly Near Infra-Red region (NIR) measurement with spectroscopy methods. This project describes pathology of Diabetes Mellitus, specifies how it is divided, and looks also on human metabolism. The theoretical part contains exploration of blood glucose measurement methods. Thesis continues with system scheme design for non/invasive glucose measurement device, based on present knowledge. Major principle of device is measuring with Infra-Red laser, bifurcate optic fiber and photodiode. Design of printed circuit board is also present. Document contains also designs of software diagrams for calibration and processing program written in C# language. Communication between device and computer is made via USB. Microcontroller with C language program is part of designed device. It is used to send measured values into PC and also receives data from computer. This data determines blood glucose concentration and their thresholds.
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Electrochemical biosensor for glucose detection
Matula, Tomáš ; Majzlíková, Petra (referee) ; Prášek, Jan (advisor)
This thesis pays attention to electrochemical sensors for the detection of glucose. The theoretical part deals with the technology of thick film, their application and firing. It is further described electrochemistry, electrodes used in electrochemistry and analytical methods based on electrochemical reaction. End of theoretical part deals with electrochemical biosensors for detection glucose using special electrodes based on enzyme glucose oxidase. In the experimental part is processed amperometric measure for detection glucose using screenprinted sensors S10 and S8 with immobilized enzyme glucose oxidase. Next was studied effect of plasma, dissolved potassium chloride, storage, ascorbic acid and the reproducibility of the sensors.
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Influence of disinfectants on the content of lactic acid in the production of refined sugar
Novotná, Hedvika ; Skoumalová, Petra (referee) ; Horák, Radek (advisor)
The diploma thesis compares the effectiveness of disinfectants on the content of the lactic acid. The disinfectants used for the experimental part are formalin and BetaStab®. The content of glucose and lactic acid was observed and compared after processing conventional beet and bio-beet. Based on the analysis of the measured data, it was found that the highest disinfecting effect on the lactic acid content had formalin, the avearge lactic acid value was 275 mg/l. In experiment with BetaStab® disinfection the average value of the lactic acid was 350 mg/l. When the beet was processed without the use of disinfection, this average lactic acid was 371 mg/l and in the untreated treatment of the bio-beet, the lactic acid content was 467 mg/l. The glucose content of formalin disinfection diffusion juice reached an average of 573 mg/l. When BetaStab® disinfection was applied, the average glucose content was 348 mg/l and a similar value was measured for the bio-beet treatment (328 mg/l). The highest glucose content had untreated conventional beet, where an average value of 690 mg/l was reached.
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