|
|
Optical responses of biomolecules on regular metal plasmonic nanostructures
Šubr, Martin ; Procházka, Marek (advisor) ; Michl, Martin (referee) ; Valenta, Jan (referee)
Title: Optical Responses of Biomolecules on Regular Metal Plasmonic Nanostructures Author: Martin Šubr Department: Institute of Physics of Charles University Supervisor of the doctoral thesis: prof. RNDr. Marek Procházka, Dr., Institute of Physics of Charles University Abstract: Adsorption of molecules on metal plasmonic nanostructures leads to significant enhancement of many optical processes, such as Raman scattering (surface-enhanced Raman scattering - SERS) or fluorescence (surface-enhanced fluorescence - SEF). Two groups of substrates were tested within this thesis: (i) Silver nanorods prepared by oblique angle vapor deposition, and (ii) silver and gold nanoislands growing on magnetron-sputtered polytetrafluoroethylene film. Step-by- step optimization process was performed on the nanoislands in order to obtain optimum SERS sensitivity and reproducibility. Detailed SERS intensity profiles were obtained using gradient nanostructures with the localized surface plasmon resonance (LSPR) condition varying across the sample and three different excitation wavelengths. It was also found that spectral position and height of the LSPR band can be controlled simultaneously using mixed gold/silver nanoislands. Detailed investigation of polarization- and angular- dependences of anisotropic silver nanorods was...
|
|
|
Nanostructured sensors for detection of organic compounds
Šťávová, Karolína ; Fohlerová, Zdenka (referee) ; Hrdý, Radim (advisor)
This bachelor's thesis is focused on the fabrication of sensitive layers composed of an array of gold nanorods and their modifications. Firstly, a nanoporous mask is made from a layer of aluminum using a method called anodic oxidation. Afterwards electrochemical deposition of gold and polypyrrole or gold and mercury is carried out into the mask. The sensitive layer is characterized by the scanning electron microscopy and other methods for elemental analysis. A sensor with this type of sensitive layer can be used for the detection of various organic compounds.
|
|
|
Preparation of zinc oxide nanorods colloid from thin layers
Mičová, Júlia ; Remeš, Zdeněk ; Chang, Yu-Ying ; Neykova, Neda
The interest in ZnO (zinc oxide) nanoparticles is increasing due to low cost of their processing as well as the ability of fabricating ZnO nanostructures with controllable morphology such as size, shape and orientation. Our choice of method of the preparation of the nanostructured thin ZnO layers is the hydrothermal growth of ZnO nanorods on glass substrates coated by the nucleation layer deposited by the reactive magnetron sputtering. We have developed and optimized conditions of the thin layer growth with controllable dimensions of nanorods followed by the ultrasound peeling. The colloid of ZnO nanorods was characterized by measuring the size of particles using the dynamic light scattering (DLS) and the scanning electron microscopy (SEM). We found that the dynamic light scattering (DLS) can’t be directly used for size evaluation of ZnO nanorods due to their non- sperical shape. \n
|
|
|
Electrode Active Materials for Lithium-Ion Accumulators
Čech, Ondřej ; Oriňáková, Renáta (referee) ; Paidar,, Martin (referee) ; Sedlaříková, Marie (advisor)
This doctoral thesis deals with synthesis and characterisation of electroactive electrode materials for li-ion batteries and accumulators. The work is divided into two main parts. One deals with LiFePO4 based cathode composite electroactive material and in the second is described the synthesis and utilization of monoclinic TiO2(B) as an anode for li-ion cell. The main aim of the work is to relate the synthesis procedure and structural properties of both materials to its electrochemical preformance.
|
|
|
Preparation Techniques and Characterization of Electrodes with Nanostructured Surface
Hrdý, Radim ; Trnková, Libuše (referee) ; Janderka,, Pavel (referee) ; Hubálek, Jaromír (advisor)
Nowadays, nanostructures fixed on solid substrates and colloidal nanoparticles permeate through all areas of human life, in area of sensors and detection as well. This dissertation thesis deals with the fabrication of nanostructures on the surface of planar electrodes via self-ordered nanoporous template of aluminum trioxide. The nanofabrication, as one of many possible techniques, is used to increase the active surface area of electrodes by creating unique surface types with specific properties. These electrodes are very perspective in the applications, such as biomolecules electrochemical detection and measurement. The transformation of aluminum layer into non-conductive nanoporous template in the process of anodic oxidation is a fundamental technique employed to obtain the array of nanostructures in this thesis. The fabrication of high quality nanoporous membranes with narrow pore size distribution on various types of metallic multilayers is one of the key experimental parts in this work. Several problems associated with the production of the thin-film systems, including the dissolving the barrier oxide layer, are discussed and solved. Another part of this work deals with the use of nanoporous membrane as a template for the production of metallic nanostructures via electrochemical metal ions deposition directly into the pores. The obtained nanostructures as nanowires, nanorods or nanodots are characterized by the scanning electron microscopy and energy-dispersive or wavelength X-ray spectroscopy. The electrode surface, modified by gold nanostructures suitable for the detection of biomolecules, has been chosen for the electrochemical measurements, due to the gold biocompatibility. The nanostructured electrodes were characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The effect of nanostructured surface geometrical parameters, including the size of the electrochemically active area, on the results of electrochemical measurements has been observed and compared to flat gold electrodes. Two model biomolecules, namely guanine and glutathione, have been chosen for the study of potential application of these nanostructures in biosensors.
|
|
|
Synthesis of colloidal gold nanorods for biomedical applications
Valkovičová, Jiřina ; Bernard, Vladan (referee) ; Drbohlavová, Jana (advisor)
Diplomová práce se zabývá výrobou a využitím zlatých koloidních nanotyčinek v biomedicínských aplikacích. Konkrétně se zaměřuje na tři základní funkce nanočástic v analýze - transportní, separační a především zobrazovací. V části o využití nanočástic pro zobrazování je hlavní zájem věnován zejména povrchové plazmonové rezonanci zlatých nantyčinek. Dále je práce zaměřena na využití nanotyčinek pro termální terapii. Následující část je věnována vhodným modifikacím povrchu, hlavně za účelem zmírnění toxicity částic. Závěrem teoretické části jsou způsoby přípravy zlatých koloidních nanotyčinek a techniky jejich následné analýzy. V navazující experimetální části jsou uvedeny postupy, podmínky a výsledky provedených pokusů.
|
|
|
Nanostructured surfaces for electrochemical detection
Dzuro, Matej ; Hrdý, Radim (referee) ; Drbohlavová, Jana (advisor)
This work deals with the preparation of gold nanostructures for future usage in electrochemical sensors and biosensors, methods for their characterization and production. The emphasis is focused on the template-based electrodeposition method of gold and on study of the effect of manufacturing conditions on physical properties, mainly electrical and topological of nanostructures. Thesis is focused also on overall function and sensitivity of the gold nanostructured electrode.
|
guest ::
