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Optimization of new active surfaces based on plasmonic nanoparticle assemblies for SERS, SERRS and surface-modified luminescence studies of selected molecules
Sutrová, Veronika ; Vlčková, Blanka (advisor) ; Procházka, Marek (referee)
Two types of 3-dimensional (3D) Ag nanosponge aggregates were prepared and tested as samples for surface-enhanced Raman scattering (SERS) and as active surfaces for surface- enhanced luminescence. 3D Ag nanosponge aggregates were assembled from 2D fused fractal aggregates (D = 1.87 ± 0.02) prepared by modification of Ag nanoparticle (NP) hydrosol resulting from the reduction of AgNO3 by NH2OH·HCl. For SERS measurements, 3D Ag nanosponge aggregates with incorporated [Ru(bpy)3]2+ cations and chloride anions were prepared and overlayed by a thin layer of aqueous phase. For SEL measurements, the 3D Ag nanosponge aggregates were assembled from fused fractal aggregates of chloride- modified Ag NPs. After preparation the active surface was overlayed by a 1×10-5 M aqueous solution of [Ru(bpy)3]2+ . The SERRS (1×10-15 M) and SER(R)S (1×10-14 M) limits of detection of [Ru(bpy)3]2+ determined at 445 and 532 nm excitations, respectively, correspond to the single molecule level of the complex detection. Its achievement is attributed to a large electromagnetic mechanism enhancement experienced by [Ru(bpy)3]2+ incorporated in "hot spots", an efficient localization of "hot spots" in the 3D aggregate to the focus of the laser beam in micro-Raman spectral measurements and to a molecular resonance contribution to the...
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Disease and diagnosis of cardiovascular system
Procházka, Marek ; Jelen, Karel (advisor) ; Lopot, František (referee)
Disease and diagnosis of cardiovascular system Abstract In this bachelor's thesis, we are dealing with cardiovascular diagnostic methods and the most common diseases affecting the cardiovascular system. The text briefly introduces the basic diagnostic methods of the cardiovascular system. Furthermore, we focus on the most common heart diseases and possible diagnosis using these methods. Out of these diagnostic methods, we will focus on the CVS method (Classification of cardiovascular system), which is developed by the Institute of Thermomechanics AS CR in cooperation with the Faculty of Physical Education and sport, from which we are expecting in future the prediction of hypertension. This work also serves as a theoretical basis for the future experimental part of the research. Keywords: atherosclerosis, hypertension, diagnostic methods of cardiovascular system, diseases of cardiovascular system, CVS
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Preparation of plasmonic nanoparticles in non-aqueous environments and in water using chemical way and by laser ablation and their testing
Hochmann, Lukáš ; Šmejkal, Petr (advisor) ; Procházka, Marek (referee)
Příprava nanočástic (N) se stala význačnou oblastí chemie díky unikátním vlastnostem, které tyto částice mají a které vedou k širokému okruhu možných aplikací. N se běžně používají v katalýze, elektronice, fotonice a nachází se i v mnoha předmětech běžné denní potřeby. Navíc, vzhledem ke svým plasmonickým vlastnostem, se N ušlechtilých kov· hojně používají ve spektroskopii, kupříkladu při povrchově zesíleném Ramanově rozptylu (SERS). V závislosti na plánovaném použití N lze k jejich přípravě použít více cest. V pří- padě přípravy N v kapalinách (koloid·) lze použít r·zné metody chemické redukce. Tyto metody jsou dobře zavedené postupy, obzvláště ve vodném prostředí. Pro určité aplikace by však byly příhodnější koloidy v jiných rozpouštědlech. Proto je hlavním cílem této práce zhodnotit možnosti přípravy koloid· chemickou redukcí a laserovou ablací ve vodě a organick- ých rozpouštědlech. Dalším cílem je charakterizace připravených částic a zhodnocení jejich potenciálu pro SERS. Zlaté koloidy ve vodě a alkoholech byly připraveny redukcí kyseliny tetracholoro zlatité tetrahydridoboritanem sodným. K přípravě stabilních sol· v alkoholech byl dále nutný pří- davek polyvinylpyrrolidonu (PVP) jako stabilizátoru, protože přímá příprava koloid· chemickou redukcí v alkoholech vedla k jejich kolapsu. Dále...
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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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HDO Raman spectrum
Šubr, Martin ; Štěpánek, Josef (advisor) ; Procházka, Marek (referee)
Title: HDO Raman spectrum Author: Martin Šubr Department: Institute of Physics of Charles University Supervisor: Prof. RNDr. Josef Štěpánek, CSc., Institute of Physics of Charles University Abstract: The main aim of this thesis is to determine the HDO Raman spectrum. This spectrum cannot be measured separately in its liquid form, but it is possible to obtain it by a specific mathematical processing of sets of measured spectra with different H/D ratios. In this work we measured Raman spectra of liquid water with different mole fractions of water and heavy water, which were evaluated by factor analysis. Except for well-known spectra of water and heavy water, spectrum of HDO was determined. For fitting of this spectrum and its analysis, model with equilibrium constant and linear correction of the spectral shape with respect to the relative ratio of D was used. Keywords: Raman scattering, water and heavy water, HDO, factor analysis
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Optimization of surface-enhanced Raman scattering spectroscopy for study of biologically important biomolecules and their interactions
Šmídová, Natália ; Procházka, Marek (advisor) ; Vlčková, Blanka (referee) ; Michl, Martin (referee)
Title: Optimization of surface-enhanced Raman scattering spectroscopy for study of biologically important biomolecules and their interactions Author: Natália Šmídová Department: Institute of Physics of Charles University Supervisor of the doctoral thesis: Doc. RNDr. Marek Procházka, PhD. Abstract: The main goal of this thesis was to optimize surface-enhanced Raman scattering (SERS) spectroscopy for study of biologically important biomolecules. For that purpose we focused on substrates based on gold colloidal nanoparticles immobilized to silanized glass plates. Stable, uniform and highly reproducible SERS-active substrates have been prepared by using aminopropyltrimethoxysilane and citrate- reduced gold nanoparticles thermally stabilized after their immobilization. Model biomolecules 5,10,15,20-tetrakis(1-methyl-4-pyridyl)porphyrin (TMPyP) and 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TSPP) were studied on these substrates by using a classical Raman spectrometer in macro-mode and a confocal Raman microspectrometer. Conditions for SERS spectroscopy of porphyrins were optimized with respect to sensitivity and reproducibility. SERS microspectroscopy showed several advantages over SERS measurements in macromode: possibility of surface spectral mapping, easier manipulation with samples, shorter...
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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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Intensity Normalization of Raman Spectra by Means of Various Internal Standards
Sláma, Vladislav ; Mojzeš, Peter (advisor) ; Procházka, Marek (referee)
The work deals with the testing of selected inorganic anions as internal standards for intensity normalization of Raman spectra. Using the concentration and temperature series of aqueous solutions of PO4 3- , (CH3)2AsO2 - , NO3 - a SO4 2- , impact of the spectral changes of the standard bands for reliability and accuracy of the intensity calibration was studied. Temperature and concentration series of the anion Raman spectra are then used to test normalization by means of the bands of stretching and deformation vibrations of water molecules. In addition, reliability and robustness of the calibration procedures exploiting different spectral parameters present in the Raman spectra of standards was tested. Results of the study reveal possible sources of artifacts and misinterpretations arising from insufficient understanding of the standard behavior due to changes of the physical and chemical parameters, or due to improper calibration procedure applied.
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Nanotechnology: Implementation of contemporary progress into science education at secondary school and in education of future chemistry teachers
Hájková, Zdeňka ; Šmejkal, Petr (advisor) ; Procházka, Marek (referee)
This rigorous thesis is focused on possible ways how to implement interesting and important findings from the field called "nanoworld" into the curriculum of science subjects at secondary school. For this purpose the following materials were prepared: an educational text (which also serves as a theoretical base that summarises basic information about nanotechnology and nanoscience), a multimedia Power- Point presentation, a concept of a project "When you say NANOTECHNOLOGY...", a concept of an excursion, motivational and developing interdisciplinary tasks with the theme "nano", two tests aimed at nanotechnology and advanced microscopy techniques (electron microscopy and scanning probe microscopy) and simply demonstrations. The proposed project was tested at two grammar schools in Prague. The excursion was also realized and evaluated. Both the project as well as the excursion met with an average response from students. This thesis is accompanied by a CD with the presentation and print versions of the project, pre-test, post-test and worksheets for the excursion, interdisciplinary tasks and test items. In addition, the CD contains photos and students work from the realization of the pro- ject. Furthermore, this thesis includes the questionnaire "Teach (learn) about "nano" - YES or NO?" (with...
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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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