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Fabrication and characterisation of silver decorated TiO2 nanotubes for biomedical applications
Bílek, Ondřej ; Horynová, Miroslava (referee) ; Fohlerová, Zdenka (advisor)
This diploma thesis summarizes knowledge from the fields of synthesis, characterization and application of titanium dioxide nanotubes and its combination with silver nanoparticles for biomedical purposes. Basic protocols of working with cell cultures and bacteria are also included. Experimental part of this diploma thesis focuses mainly on the synthesis of tubular structures made of titanium dioxide via anodic oxidation of 500nm titanium layer and their subsequent decoration with silver by electrodeposition. Last section of the experimental part is devoted to testing of antibacterial properties of the new material and examining the effect of different silver concentrations on the adhesion of MG-63 cells. All results are compared to reference samples consisting of titanium dioxide nanotubes without silver.
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Study of gas influence on nanoparticle generation by electrical discharge in liquids
Simić, Sanja ; Horák, Jakub (referee) ; Kozáková, Zdenka (advisor)
The work is focused on the preparation and characterization of Ag nanoparticles generated by plasma of the electric discharge in liquids. In more detail, it examines the DC discharge and the formation of hydroxyl and hydrogen radicals. The process is chemical in situ reduction, which is one of the most important methods of producing Ag nanoparticles because it is simple and economical and can perform better dimension size control by optimizing experimental parameters. During experiments, changes were made in various parameters such as concentration, conductivity, solution pH, intensity and polarity of the applied voltage. Different parameters such as particle size, shape, specific surface, crystallinity and many others can affect the properties of the nanoparticles. In view of these facts, detailed analysis of both plasma and nanoparticles generated for the control of nanoparticle synthesis and subsequent application is essential. In this work a plasma analysis was performed by optical emission spectroscopy (OES) and the characteristics of nanoparticles by UV-VIS spectroscopy and scanning electron microscopy (SEM). Silver nanoparticles are used in many industries such as the food, textile, construction and energy industries as well as in medicine, cosmetology and pharmacy. Thanks to their widespread use they represent the future of nanotechnology.
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Surface-enhanced resonance Raman scattering of Zn(II) porphyrins in systems with aggregated and non-aggregated Ag nanoparticles
Spáčil, Dušan ; Vlčková, Blanka (advisor) ; Procházka, Marek (referee)
In this diploma thesis, SERRS(Surface - enhanced resonance Raman Scattering) and SERS (Surface - enhanced Raman Scattering), surface of plasmon extinction spectra and TEM images of systems with tetracationic zinc porphyrin ZnTMPyP and silver nanoparticles (Ag NPs) were studied and interpreted. The systems with isolated nanoparticles and the systems with compact aggregates were investigated. The systems with isolated nanoparticles were prepared by addition of ZnTMPyP to hydrosol of Ag NPs. NaCl was added to this system and so compact aggregates were prepared. SERRS and SERS spectra of ZnTMPyP were studied at excitation wavelengths λexc= 441.6 nm a 532 nm. Firstly, stationary systems and secondly dynamic development of hydrosol Ag NPs → Ag NPs/ ZnTMPyP → Ag NPs/ ZnTMPyP/ NaCl systems for 680 s was investigated. Time evolution of SERRS and SERS spectra were analyzed by factor analysis (FA) and time evolution of spectra extinction plasmon were measured. FA showed a strong increase of the signal of ZnTMPyP after the addition of NaCl, i.e. after conversion of isolated nanoparticles to compact aggregates. In these systems with high concentration of ZnTMPyP the increase of signal was succeeded by its decreased. With help of FA the limit of SERRS spectral detection (λexc= 441,6 nm) and limit of SERS spectral...
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Study of gas influence on nanoparticle generation by electrical discharge in liquids
Simić, Sanja ; Horák, Jakub (referee) ; Kozáková, Zdenka (advisor)
The work is focused on the preparation and characterization of Ag nanoparticles generated by plasma of the electric discharge in liquids. In more detail, it examines the DC discharge and the formation of hydroxyl and hydrogen radicals. The process is chemical in situ reduction, which is one of the most important methods of producing Ag nanoparticles because it is simple and economical and can perform better dimension size control by optimizing experimental parameters. During experiments, changes were made in various parameters such as concentration, conductivity, solution pH, intensity and polarity of the applied voltage. Different parameters such as particle size, shape, specific surface, crystallinity and many others can affect the properties of the nanoparticles. In view of these facts, detailed analysis of both plasma and nanoparticles generated for the control of nanoparticle synthesis and subsequent application is essential. In this work a plasma analysis was performed by optical emission spectroscopy (OES) and the characteristics of nanoparticles by UV-VIS spectroscopy and scanning electron microscopy (SEM). Silver nanoparticles are used in many industries such as the food, textile, construction and energy industries as well as in medicine, cosmetology and pharmacy. Thanks to their widespread use they represent the future of nanotechnology.
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Development and testing of new types of active surfaces for investigation of surface-modified optical processes of biologically important molecules
Sutrová, Veronika ; Vlčková, Blanka (advisor) ; Procházka, Marek (referee)
Hydrosols of silver nanoparticles (AgNPs) prepared by reduction of AgNO3 by either NaBH4 (BH-AgNP hydrosol), or NH2OH·HCl (HA-AgNP hydrosol) modified by the addition of HCl were characterized by SPE spectra (SPE = surface plasmon extinction) and transmission electron microscopy, and their SERS (Surface-enhanced Raman Scattering) activity was tested by measuring the SERS or SERRS (Surface-enhanced Resonance Raman Scattering) spectra of 2,2'-bipyridine (bpy) and 5,10,15,20-Tetrakis(1-methyl-4-pyridinio)-21H,23H-porphine (H2TMPyP) testing adsorbates and by determining of their SERS and SERRS spectral detection limits at λexc = 532 nm. For both types of AgNP hydrosols, it was found that the addition of HCl and the addition of testing adsorbate leads to an intergrowth of AgNPs and to the formation of their compact aggregates, in combination with the formation of new Ag(0) adsorption sites. The limit of detection in a macrosampling setup was 1·10-9 M in the system HA-AgNP hydrosol /HCl/bpy and 1·10-5 M in the system BH AgNP hydrosol/HCl/bpy and, in both causes the Ag(0)-bpy surface complex was detected. About one order of magnitude lower detection limit of bpy in the system with HA-AgNP hydrosol is caused by the efficient intergrowth of AgNP in HA-hydrosol resulting into an efficient formation of "hot...
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Fabrication and characterisation of silver decorated TiO2 nanotubes for biomedical applications
Bílek, Ondřej ; Horynová, Miroslava (referee) ; Fohlerová, Zdenka (advisor)
This diploma thesis summarizes knowledge from the fields of synthesis, characterization and application of titanium dioxide nanotubes and its combination with silver nanoparticles for biomedical purposes. Basic protocols of working with cell cultures and bacteria are also included. Experimental part of this diploma thesis focuses mainly on the synthesis of tubular structures made of titanium dioxide via anodic oxidation of 500nm titanium layer and their subsequent decoration with silver by electrodeposition. Last section of the experimental part is devoted to testing of antibacterial properties of the new material and examining the effect of different silver concentrations on the adhesion of MG-63 cells. All results are compared to reference samples consisting of titanium dioxide nanotubes without silver.
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Development and optimization of systems for SERS on single molecule level
Michlová, Magdalena ; Vlčková, Blanka (advisor) ; Pfleger, Jiří (referee) ; Procházka, Marek (referee)
AABBSSTTRRAACCTT Dimers and small aggregates as well as compact aggregates of Ag nanoparticles (NPs) were assembled and chemically anchored to supporting surfaces. The supporting surfaces were either glass slides or SiO2 - coated Cu or Au grids for TEM, both chemically functionalized by 3-aminopropyltrimethoxysilane (APTMS). Compact aggregates of Ag NPs incorporating protoporphyrin IX (PPIX) molecules were prepared by adsorption of chlorides in the presence of PPIX. Dimers and small aggregates of Ag NPs were assembled by selected molecular linkers: 4,4'-diaminoazobenzene (DAAB), 4,4'-diaminoterphenyl (DATP) and 5,10,15,20-tetrakis(4-aminophenyl)porphine (TAPP). The most efficient strategy of dimers and small aggregates preparation has been their assembling by a three - step procedure involving (i) attachment of isolated Ag NPs to the NH2 groups of APTMS functionalized TEM grid, (ii) attachment of molecular linker (with two functional NH2 groups in para position) to Ag NPs by a one terminal NH2 group, and (iii) attachment of Ag NPs to the second, free terminal NH2 group of the linker. In this procedure, the control over the perpendicular orientation of the bifunctional linker and its attachment by one terminal group to Ag NP surface has been accomplished by functionalization of Ag NPs by adsorbed citrate...
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Surface-enhanced resonance Raman scattering of Zn(II) porphyrins in systems with aggregated and non-aggregated Ag nanoparticles
Spáčil, Dušan ; Vlčková, Blanka (advisor) ; Procházka, Marek (referee)
In this diploma thesis, SERRS(Surface - enhanced resonance Raman Scattering) and SERS (Surface - enhanced Raman Scattering), surface of plasmon extinction spectra and TEM images of systems with tetracationic zinc porphyrin ZnTMPyP and silver nanoparticles (Ag NPs) were studied and interpreted. The systems with isolated nanoparticles and the systems with compact aggregates were investigated. The systems with isolated nanoparticles were prepared by addition of ZnTMPyP to hydrosol of Ag NPs. NaCl was added to this system and so compact aggregates were prepared. SERRS and SERS spectra of ZnTMPyP were studied at excitation wavelengths λexc= 441.6 nm a 532 nm. Firstly, stationary systems and secondly dynamic development of hydrosol Ag NPs → Ag NPs/ ZnTMPyP → Ag NPs/ ZnTMPyP/ NaCl systems for 680 s was investigated. Time evolution of SERRS and SERS spectra were analyzed by factor analysis (FA) and time evolution of spectra extinction plasmon were measured. FA showed a strong increase of the signal of ZnTMPyP after the addition of NaCl, i.e. after conversion of isolated nanoparticles to compact aggregates. In these systems with high concentration of ZnTMPyP the increase of signal was succeeded by its decreased. With help of FA the limit of SERRS spectral detection (λexc= 441,6 nm) and limit of SERS spectral...
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