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Biosensors based on modified TiO2 nanoparticles
Valkovičová, Jiřina ; Adam, Vojtěch (referee) ; Hubálek, Jaromír (advisor)
The work is focused on quantum dots (QDs) array fabrication from titanium dioxide using template based non-lithographic method and their luminescence (fluorescence) properties study. The paper describes TiO2 QDs surface modification with gold using suitable template technique and subsequent functionalization of gold modified QDs surface via oligonucleotides. This functinalization step provides a suitable base for subsequent hybridization reaction with detected nucleic acid. The system of biosensor (TiO2 QDs modified with gold and biomolecules) is designed for rapid optical diagnosis of viral diseases.
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Study of influence of quantum dots to biological systmes and their components
Koudelková, Zuzana ; Zítka, Ondřej (referee) ; Provazník, Ivo (advisor)
The aim of this thesis is to summarize the available evidence about quantum dots and their effects on living systems. The text describes methods for the preparation of quantum dots with respect to their characteristics (size, fluorescence wavelength) and methods of quantum dots bio-functionalization of biomolecules. In living organisms is a large number of proteins, because these are considered as one of the main components of the interaction of organisms. Therefore, the work also provides basic information about proteins. Finally, there are described various methods by which the quantum dots may be characterized mainly by differential pulse voltammetry measurement zeta potential and fluorescence measurement. The main objective of this work is to propose models of different environments in which will be degradation of quantum dots with regard to the evaluation of acquired kinetic parameters for predicting the stability of individual quantum dots.
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Study of UV-generated fluorescent zinc complexes by fluorescence spectroscopy
Havlíková, Martina ; Vaculovičová, Markéta (referee) ; Mravec, Filip (advisor)
This thesis focuses on the study of UV light-generated zinc complexes with cadmium and organic molecules SAM, SAH, CYS, HCYS and GSSG, specifically at 375 nm. Furthemore, the aim of the work is to characterize the precursors spectrally and temporally before and after irradiation in the transilluminator at 250 nm. Study of genesis these complexes was performed by FLIM. Thanks to this method, it was found that the formation of complexes occurs only with Zn:SAH, Zn:GSSG and Zn:Cd. The formation of complexes is influenced by the method of preparation. The spectral characteristic was performed on a fluorimeter where the increase in fluorescence intensity of the irradiated solution with the precursors was expected. These were turbid solutions where sedimentation of the particles was observed and the intensity of fluorescence was changed. In the Zn:SAM and Zn:CYS sample, the sedimentation increased in intensity, while in Zn:SAH and Zn:HCYS decreased. The Zn:Cd precursor solution was clear and there was no change in intensity. Zn:Cd showed the best spectral properties, while the Zn:SAM sample, whose excitation and emission maxima are very close to each other, appeared to be the worst. A sample with Zn:CYS and Zn:HCYS showed almost the same spectra and respective peak results. Based on lifetime characteristics by TCSPC, the sample with Zn:CYS, Zn:HCYS and Zn:GSSG, which showed 3 lifetimes, was best treated. Lifetime could not be unambiguously determined for SAM and SAH samples. Zn:Cd had 4 lifetimes
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Development of Instrumentation and Methodology in Proteomic and Environmental Analysis
Hezinová, Věra ; Bobáľová, Janette (referee) ; Lubal,, Přemysl (referee) ; Čáslavský, Josef (referee) ; Klepárník, Karel (advisor)
Tato práce je zaměřena jak na cílený tak na přehledný přístup ve studiu proteomiky. Cílená proteomika přináší informace o přítomnosti proteinu a jeho lokalizaci v buňce či tkáni pomocí luminiscenčních značek na bázi kvantových teček, zatímco přehledná proteomika se zabývá identifikací změn v proteomu dvou nebo více jedinců stejného druhu vystavených různým podmínkám. Protože proteomika vyžaduje vysoce citlivé separační a identifikační techniky, byly v této práci ověřeny různé metody zlepšení citlivosti kapilární elektroforézy s hmotnostní detekcí. Použití rozhraní s kapalinovým spojem pro spojení těchto dvou technik, které zajišťuje vyšší citlivost analýz, bylo také ověřeno analýzou metabolitů etanolu a kokainu v lidské moči. Zavedené techniky instrumentace jsou využitelné při posouzení vlivu významných faktorů životního prostředí na živé systémy jak na buněčné tak na molekulární úrovni.
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Study of metallothionein conjugates by electromigration methods
Johaníková, Klára ; Zemánková, Kristýna (referee) ; Vaculovičová, Markéta (advisor)
The bachelor thesis deals with the study of conjugates of metallothionein (MT) with fluorescent nanoparticles using electromigration methods. Particular attention is paid to the preparation and characterization of quantum dots (QDs) and their bioconjugates with the metallothionein protein, whose separation conditions (concentration and suitable electrolyte pH) have been carefully optimized. For the preparation of QDs, the action of UV radiation for one type of quantum dots and the thermal action of high temperature for the second type of species were used. Conjugation of QDs to the protein was performed via a carbodiimide-zero-length crosslinker (EDC / sulfo-NHS), which activates carboxyl groups and allows bioconjugation of the ligand by covalent bonding. The resulting bioconjugates were studied by capillary electrophoresis with absorption detection ( 214).
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Use of nanomaterials to improve optical detection of biomolecules
Špačková, Simona ; Kristýna, Pavelicová (referee) ; Bezděková, Jaroslava (advisor)
The bachelor thesis deals with modern methods of biomolecule labeling. Attention is paid especially to luminescent labeling with semiconductor quantum dots, optimization of preparation and characterization of quantum dots (QDs) and their bioconjugates with Ala4 peptide, which has antibacterial properties. The first method of preparing QDs used UV-radiation and conjugation with the peptide of interest was carried out through the thiol group of the peptide. A second type of QDs was prepared thermally and conjugation with the peptide was performed by linkers EDC/sulfo-NHS, which allowed peptide bond formation between the carboxyl group of QDs and the amino group of the peptide. The next part of the thesis is focused on the influence of conjugation the antimicrobial activity of the peptide. To verify the antimicrobial properties of the peptide, an interaction between the QDs-Ala4 conjugate and Staphylococcus aureus was observed. Conjugates thus prepared were characterized by fluorescence spectroscopy and capillary electrophoresis with absorption detection (-214 nm).
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Biofyzikální studium malých RNA
Šmerková, Kristýna
Thanks to the prove of connection between the aberrant occurrence of small RNA and various diseases and their potential in diagnostics and treatment led to discovery of new methods and materials facilitating their detection and targeted transport during gene therapy. This work summarizes present knowledge about chosen groups of small RNA, their significance in medical science and the possibilities of their detection. This work primarily concentrates on combination of magnetic separation with electrochemical detection. Magnetic particles (MPs) with different surface modifications were used for isolation. Non-specific isolation was carried out using silanol-coated MPs; streptavidin-coated MPs modified with specific biotinylated probe were used for specific separation. Square wave voltammetry (SWV) was used as a very sensitive electrochemical detection method. Optimized method based on specific magnetic separation with SWV was able to reach nanomolar detection limit (4 nM) with microRNA. The method was applied on human embryonic cells for specific isolation and detection of miR-124. The CdTe quantum dots (QDs) were studied as a nanomaterial tool for nucleic acid detection. The QDs were modified with streptavidin for their bioconjugation with biotinylated molecules were used. Interaction of QDs with nucleic acids was studied using capillary electrophoresis.
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Quantum dots and their interaction with biomolecules
Stanisavljević, Maja
In this study CdTe QDs were synthetized via microwave irradiation method. Further they have been modified for purposes of their interaction with biomolecules using different conjugation approaches. Applied conjugation chemistries were non-specific interaction, streptavidin-biotin affinity. Glutathione modified CdTe QDs of 2 nm size were capable of non-specific interaction with major groove of DNA, while streptavidin modified CdTe QDs served as specific linker for biotinylated oligonucleotides. Further, streptavidin-biotin interaction was used for coupling of apoferritin and magnetic nanoparticles.
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Použití spektroskopických technik pro studium interakcí platinových komplexů a nanočástic s nukleovými kyselinami =: Interactions study of nanoparticles and platinum complexes with nucleic acids assessed by spectroscopic techniques /
Nejdl, Lukáš
The ability of the metal ions to form a covalent bond with the nucleic acids (DNA or RNA) is critical for their structural properties and functions. In the 60s of the last century the potential of platinum complexes in anticancer therapy was revealed. The success of these complexes in anticancer treatment is given by their ability to bind to the DNA bases to form different types of coordination covalent bonds. The formation of these bonds results in an interference of the DNA secondary structure and thereby blocking of important cellular processes such as replication or transcription. Presented thesis examines the ability of metal and semimetal ions (Zn(III), As(III) and As(V)), platinum nanoparticles (PtNPs) and cadmium-based quantum dots (QDs-CdS) to influence the DNA secondary structure. In this work the interactions of metal ions with DNA were firstly investigated due to the implementation and verification of instrumental methods. Results of these studies served as the basis for subsequent experiments dealing with the effects of nanoparticles on eukaryotic cells with regard to DNA damage. In this work we demonstrated that PtNPs show higher affinity for DNA polymerases than to DNA. For this reason, PtNPs can arrest the cell cycle and trigger apoptosis. The affinity rate of nanoparticle binding to DNA is determined by its size, as was shown by the experiments with variously sized CdS-QDs.
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New pathways to plasmonic nanoparticle assembling into 2D and 3D hybrid active systems for SERS of graphene and SERS, SERRS and GERS + SERS of aromatic molecules
Gajdošová, Veronika ; Vlčková, Blanka (advisor) ; Němec, Ivan (referee) ; Michl, Martin (referee)
In the first part of the Thesis, a new type of active system for SERS and SERRS of hydrophobic molecules, namely a 3-dimensional (3D) nanosponge aggregate with incorporated hydrophobic molecules has been developed, and tested by fullerene C60 and hydrophobic free- base tetraphenylporfine (H2TPP). The SERS and SERRS (surface enhanced /resonance/ Raman scattering) limits of detection (LODs) of C60 at four excitation wavelengths spanning the visible spectral region were found to be by one order of magnitude lower than in the reference system, which mimics the previously reported ways of utilization of Ag nanosponges as substrates for SERS and SERRS. The superiority of the newly developed sample is attributed to the efficient localization of the hydrophobic molecules into hot spots in 2D fractal aggregates of Ag nanoparticles (NPs). Diprotonation of H2TPP during the procedure using HCl as the preaggregation agent has been eliminated by employment of NaCl. On the other hand, investigation of the mechanism of H2TPP protonation during the former preparation procedure opened a possibility to employ Ag nanosponge aggregate as nanoreactor. In the second part of the Thesis, 2D assemblies of AgNPs were found to be better substrates for SERS of single layer graphene (SLG) than the 3D ones. In particular, the 2D...
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