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Enzyme-Based Impedimetric Biosensor dotted with gold nanoparticles
Košelová, Zuzana ; Fohlerová, Zdenka
This research delves into the realm of biosensor improvement through the utilization of gold nanoparticles (Au NPs). The primary objective is to assess the impact of differentsized Au NPs on sensor performance, specifically investigating whether 100 nm or 20 nm nanoparticles prove more favourable to enhancement. Moreover, we aim to inspect the biosensor's response to varied concentrations of Au NPs, unravelling the involved collaboration between nanoparticle size, concentration, and overall sensor properties. This modification of commercial electrodes with Au NPs, could be way for enhancing surface area and enzyme immobilization. Notably, the investigation also explores the potential drawbacks associated with increasing nanoparticle concentration and offers insights into optimizing biosensor design. It has been observed that while 20 nm Au NPs slightly decreased impedance values at higher glucose concentrations, 100 nm Au NPs, conversely, exhibited an increase in capacitive behaviour. Equally crucial is the parameter chosen for constructing the calibration curve. From impedance values at low frequencies of alternating voltage, such as 2 Hz, a lower Limit of Detection (LOD) is obtained. However, the analysis of Rct in the case of 20 nm Au NPs reveals a broader range of glucose concentrations falling within the calibration area. Through a comprehensive analysis of electrochemical behaviour, impedance, and charge transfer resistance, we endeavour to provide contributions to the improvement of biosensor technologies.
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Natural patterns in robotics
Juřicová, Vendula ; Augste, Jan (referee) ; Knoflíček, Radek (advisor)
This bachelor´s thesis is focused on the part of the robotics, which is inspired by nature. At first, the reader is introduced into the theory of interdisciplinary terms BIO – ING. The central part is divided in two parts: the inspiration by man and inspiration by animals. In the chapter about man, there are the main biomechanical features introduced as well as the algorithms that are used in the robotics with the human prototype. Some biomechanical constructions and humanoid robots follow. Biomechanical constructions that are inspired by animals dominate the second part. The conclusion includes (among others) a technical and a philosophical reflection on the future of the robotics.
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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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Magnetic particles as a reversible carrier for enzyme electrodes
Janíček, Zdeněk ; Žeravík,, Jiří (referee) ; Skládal,, Petr (advisor)
Master’s thesis contains information about the enzymes, biosensors, enzyme biosensors and magnetic particles. Cholinesterasa (ChE) is the generally name for the two related enzymes, mutually differing appearance and biological functions. Acetylcholinesterasa (AChE) is necessary for the transmission of nervous excitement. AChE is located at cholinergic synapses, where is the hydrolysis of the neurotransmitter acetylcholine and this termination by the nervous excitement. Butyrylcholinesterasa (BChE) is related to AChE and it is present in serum. Experimental part was focused on electrochemical biosensors with cholinesterase enzyme using magnetic particles for reversible reconstruction layer. Cholinesterase immobilization was carried out on the magnetic particles by covalent binding after glutaraldehyde activated. The measurement of activity take place with acetylthiocholin as a substrate in a flow system, magnetic particles were captured before the platinum electrode and produced by thiocholin is detected amperometric. The aim was to measure inhibition of AChE. Significant inhibition ChE is caused by certain drugs and pesticides based on organophosphates. There was tested by inhibition of AChE pesticide dichlorvos. Emphasis was on finding possible experimental conditions for the creation of the automated procedure to measure the AChE activity, which was based on auto-injector and pumps of Gilson, together with a 735 programme for the definition of the working configuration, preparation of measurement scripts and implementation of application methods.
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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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Functionalized nanostructures
Váňa, Rostislav ; Kvapil, Michal (referee) ; Kolíbal, Miroslav (advisor)
This thesis deals with functionalized nanoparticles. In the first part there are mentioned materials suitable for a functionalization, the usage of functionalized nanoparticles in medicine and biochemistry and detection methods of changes of optical properties. In the second part changes of optical properties after functionalization are investigated by spectroscopic ellipsometry and FTIR spectroscopy.
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Nanopatterned alumina-based materials for electrochemical sensors and biosensors
Kynclová, Hana ; Hynek, David (referee) ; Trnková, Libuše (referee) ; Prášek, Jan (advisor)
The doctoral thesis is focused on basic research and development of nanostructured surfaces prepared using anodic alumina material. Various types of gold nanostructured surfaces and nanoporous aluminum membranes for electrochemical sensors and biosensors were prepared using the anodic oxidation method. Nanostructured surfaces were prepared by electrochemical anodization of aluminum material to form hexagonally arranged nanopores. Gold was then deposited into the nanoporous masks by electrochemical reduction from potassium dicyanoaurate solution using a pulse deposition method. The prepared nanostructured gold surfaces were electrochemically characterized by electrochemical impedance spectroscopy and voltammetry. Temperature stability and the effect of annealing on their electrochemical behavior at atmospheric pressure as well as in the vacuum were investigated. Then, gold nanostructures of various dimensions were prepared and the influence of their shape and dimensions on the electrochemical behavior was studied. Nanostructured surfaces were also modified with 11–mercaptoundecanoic acid, and the effect of this modification on the electrochemical results was studied. In the last part of the work, nanoporous aluminum membranes were prepared, and their permeability was studied.
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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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Diagnostics of genom conditioned diseases with the use of micro- and nanoparticles
Mondeková, Věra ; Prášek, Jan (referee) ; Provazník, Ivo (advisor)
The bachelor´s thesis discusses possibilities of viral genome´s detection through use of biosensors, more specifically through use of magnetic particles. The introductory part consists of brief characteristic of viruses, mentioned as originator of genom conditioned diseases, followed by chapters related to selected methods of nucleic acid´s extraction and analysis. The main part is dedicated to magnetic particles. The practical part of thesis deals with possibility of use of biosensors in specific viral pathogen´s detection, selection of biocompatible molecules suitable for magnetic particle modification and description of specific DNA sequence isolation procedure through use of magnetic particles.
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The application of electrochemical impedance spectroscopy for investigation of enzyme kinetics
Pospíšilová, Michaela ; Sedláček, Jiří (referee) ; Fohlerová, Zdenka (advisor)
The application of electrochemical impedance spectroscopy (EIS) in theory and experiment for investigation of redox enzyme kinetics has been already described. The impedance studies are quite sensitive to the changes at the interface caused by adsorption of charged species and therefore can be used to study the kinetics of adsorption of macromolecules and also enables us to study enzyme kinetics since the action of the enzymes on their substrates involved modification and generation of charged species. In this work, we would explore the potential of electrochemical impedance technique to follow the kinetics of glucose oxidasesubstrate reactions on the immobilized surface. The enzyme will be allowed to interact with different concentrations of its substrate and the resulting reaction will be recorded in real time. Changes in the imaginary component of the impedance at various substrate concentrations will be expected to follow MichelisMenten kinetics. The experimental procedure should be simple and can be carried out directly in buffer solutions most suited for the required interaction to take place, without the requirement of any additional redox probes.
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