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Mangham, Barry. "Synthesis and analysis of fluorescent dye molecules." Thesis, University of Nottingham, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602528.
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The nature of non-covalent bonding interactions was investigated through the deposition and subsequent scanning tunnelling microscopy (STM) imaging of tetra-substituted porphyrins. Porphyrins bearing iodo, bromo, nitro, pyridyl and carboxylic acid groups were synthesised and deposited on either Au(110) or Au(l11). STM imaging and analysis showed a variety of different orientations and packing for the different functional groups. The unusual tip induced growth of honeycomb packing orientations was seen for tetra-pyridyl substituted porphyrin. Tetra-bromo substituted porphyrin was observed to adopt different ordered orientations of the saddle shape conformation on Au(111). The synthesis of novel porphyrin dimers bearing carboxylic acid groups was investigated, with a variety of different pathways being identified and explored. Furthermore, upon cooling unusual spectroscopic behaviour was observed for a hexa-phenyl substituted meso-linked porphyrin dim er. The synthesis of novel BODIPY dimers and trimers was investigated. A number of fluoro and catecholate substituted BODIPY compounds were synthesised, bearing a variety of different linkers. Linkers investigated included phenyl, biphenyl, terphenyl, durene and terphenylene. Electrochemical and spectroscopic investigations demonstrated a variety of differences between meta- and para-substitution positions. The extension of the linker length from phenyl through to terphenyl displayed a reduction in communication of BODIPY moieties. The durene linked dimer added steric bulk to the centre of the BODIPY dimer, resulting in increased fluorescence lifetimes and quantum yields. 1
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Meyer, Jörg, Anja Wadewitz, Lokamani, Cormac Toher, Roland Gresser, Karl Leo, Moritz Riede, Francesca Moresco, and Gianaurelio Cuniberti. "Molecules for organic electronics studied one by one." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138788.
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The electronic and geometrical structure of single difluoro-bora-1,3,5,7-tetraphenyl-aza-dipyrromethene (aza-BODIPY) molecules adsorbed on the Au(111) surface is investigated by low temperature scanning tunneling microscopy and spectroscopy in conjunction with ab initio density functional theory simulations of the density of states and of the interaction with the substrate. Our DFT calculations indicate that the aza-BODIPY molecule forms a chemical bond with the Au(111) substrate, with distortion of the molecular geometry and significant charge transfer between the molecule and the substrate. Nevertheless, most likely due to the low corrugation of the Au(111) surface, diffusion of the molecule is observed for applied bias in excess of 1 VDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Meyer, Jörg, Anja Wadewitz, Lokamani, Cormac Toher, Roland Gresser, Karl Leo, Moritz Riede, Francesca Moresco, and Gianaurelio Cuniberti. "Molecules for organic electronics studied one by one." Royal Society of Chemistry, 2011. https://tud.qucosa.de/id/qucosa%3A27781.
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The electronic and geometrical structure of single difluoro-bora-1,3,5,7-tetraphenyl-aza-dipyrromethene (aza-BODIPY) molecules adsorbed on the Au(111) surface is investigated by low temperature scanning tunneling microscopy and spectroscopy in conjunction with ab initio density functional theory simulations of the density of states and of the interaction with the substrate. Our DFT calculations indicate that the aza-BODIPY molecule forms a chemical bond with the Au(111) substrate, with distortion of the molecular geometry and significant charge transfer between the molecule and the substrate. Nevertheless, most likely due to the low corrugation of the Au(111) surface, diffusion of the molecule is observed for applied bias in excess of 1 V.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Tsutae, Fernando Massayuki. "Espectroscopia de correlação de fluorescência aplicada em estudos de sistemas moleculares, biológicos e celulares." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-14102016-101124/.
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A espectroscopia de correlação de fluorescência (FCS) é uma das diferentes técnicas de análise por imagens de alta resolução espacial e temporal de biomoléculas em concentrações extremamente baixas. Ela se tornou uma técnica extremamente poderosa e sensível em áreas como bioquímica e biofísica. Como uma técnica bem estabelecida, ela é utilizada para medir concentrações locais de biomoléculas, através da marcação com moléculas fluorescentes. Coeficientes de difusão e constantes cinéticas também podem ser medidos através de FCS assim como detecção de molécula única. Ela também pode dar informação precisa sobre interações de antígeno-anticorpo, ácidos nucleicos e proteínas. Através de uma combinação de marcadores de alto rendimento quântico, fontes de luz estável (lasers), detecção ultrassensível e microscopia confocal, é possível realizar medidas de FCS em volumes de fentolitros (fL) e em concentrações de nanomolar (nM) em soluções aquosas ou em células vivas. Em contraste com outras técnicas de fluorescência, a sensibilidade da FCS aumenta com a diminuição da concentração do fluoróforo marcador, porque o parâmetro de interesse não é a intensidade de emissão de fluorescência, mas sim as flutuações espontâneas da fluorescência. Durante o tempo em que a partícula ou molécula atravessa o volume de medida pode ocorrer mudanças conformacionais e reações químicas e fotofísicas que alteram as características de emissão do fluoróforo e causam flutuações no sinal detectado. Estas flutuações são então monitoradas e transformadas em uma curva de autocorrelação, por intermédio de um software comercial que emprega um modelo físico apropriado para FCS. Em nosso estudo, utilizamos um marcador comercial (ALEXA 488®) para marcar proteínas. Primeiramente utilizamos a técnica de FCS para medir concentrações extremamente baixas de marcadores fluorescentes. Também realizamos um experimento testando a influência da viscosidade do meio na difusão livre do fluoróforo, assim como as melhores condições em que temos um melhor sinal de FCS. Por fim, estudamos a difusão de proteínas marcadas (PUC II e IV) em meio aquoso (PBS) e no interior de células.Fluorescence correlation spectroscopy (FCS) is one of the many different modes of high-resolution spatial and temporal analysis of extremely low concentrated biomolecules. It has become a powerful and sensitive tool in fields like biochemistry and biophysics. As a well established technique, it is used to measure local concentrations of fluorescently labeled biomolecules, diffusion coefficients, kinetic constants and single molecule studies. Through a combination of high quantum yield fluorescent dyes, stable light sources (lasers), ultrasensitive detection and confocal microscopy is possible to perform FCS measurements in femtoliters volumes and nanomolar concentrations in aquous solution or in live cells. Unlike with other fluorescence technics, its sensibility increases with the decrease of dye concentrarion, because the main factor is not the emission intensity itself. Instead this, spontaneous statistical fluctuation of fluorescence becomes the main factor in FCS analisys. During the time that the conjugated-dye cross the volume detection can occur conformational changes, chemical reaction and photophysical processes that can change the emission properties of the dye and, then, change the detected sinal. This fluctuations are tracked and changed into a autocorrelation curve, by a specific software, appropriate to perform FCS analisys. In our study, we use comercial dye (Alexa 488) to label proteins. Firstly, we applied FCS to measure extremally diluted concentrations of dyes (~1 nM). We have performed experiments testing the influence of the viscosity medium in the free difusion of the dyes and the optical apparatus and conditions that result in the best FCS signal. We also have studied protein diffusion (PUC II e IV) in aquous medium (PBS) and toward the inner of the cells.
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Gösch, Michael. "Microfluidic analysis and parallel confocal detection of single molecules /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-663-4/.
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Kline, Katrina K. Tucker Sheryl A. "Comparison of hyperbranched and dendritic polymers with fluorescent reporter molecules." Diss., Columbia, Mo. : University of Missouri-Columbia, 2009. http://hdl.handle.net/10355/6780.
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The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 26, 2010). Thesis advisor: Dr. Sheryl Tucker. Vita. Includes bibliographical references.
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Darko, Janice. "Fluorescent Labeling of Antibiotic Resistant Bacteria Model DNA." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7600.
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Global threats to treatment of bacterial infections due to antibiotic resistance (AR) have been on the rise in recent years. Current diagnostic tests identify bacteria by using blood culture, which takes more than 24 hours. This study focuses on the fluorescent labeling of DNA derived from bacterial AR genes (KPC & VIM) and other model DNAs using oligreen dye (OG) and molecular beacons (MB). A NanoDrop 3300 fluorospectrometer was used to take fluorescence measurements. Linear dynamic range and labeling efficiency were dependent on the following optimized conditions: dilution factor of OG (200 fold), buffer (20 mM Tris HCl, pH 8), and heat treatment of 95 °C for 15 min.Fluorescence analysis of a target DNA with a designed MB showed signal-to-background of 10 with our buffer only and 20 with our buffer and 25% ethanol. I also demonstrated a simple microfluidic device capable of detecting AR genes using model DNAs, magnetic beads, and designed MBs for assays of µ50 L volume. This study provides a first step towards detecting MB-DNA complexes by a simple, low cost, and fast non-amplified method, which may be used to detect AR genes in clinical samples in the future.
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Winstanley, Thomas Peter Llewelyn. "Synthesis and study of fluorescent molecular dyes." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2324.
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Uses for fluorescent dyes are diverse and increasingly important with compounds having many uses in medicinal, chemical and physical fields - amongst others. The creation of new fluorescent dyes helps to push the boundaries of molecular photonics alongside the further study of the underlying principles involved in the systems. This thesis concentrates largely on the synthesis and characterisation aspects of novel fluorescent dyes, though the analysis of the resultant photophysical data also features prominently. Chapter 1 is an introduction to fluorescence from some of the more basic principles involved in the field. A discussion and comparison of intrinsic and extrinsic fluorescent dyes is followed by a brief discussion of a series of examples of fluorescent molecular sensors. As bodipy dyes feature heavily throughout the thesis the second half of the introduction is focused solely on this topic. This half of the chapter centres around the synthetic approaches towards bodipy, modifications to the bodipy core and the resulting photophysics. Photo-induced electron transfer and fluorescence energy transfer is introduced from basic principles along with selected literature examples that demonstrate these processes in systems that incorporate bodipy. Chapter 2 discusses the synthesis and photophysics of a new class of fluorescent dyes based on a highly substituted terephthalate core. The initial aim of the chapter was to create fluorescent systems based on a xanthene core, this was found to be non-fluorescent. As such attention was turned towards a terephthalate intermediate which demonstrated strong and highly red shifted fluorescence in solution, as well as solid state fluorescence. A meso-perfluorinated phenyl ring causes a marked increase in fluorescence quantum yield, along with a pronounced red-shift, relative to the equivalent meso-phenyl variant. This observation lead to a series of Fn-aryl (n = 1,2,3,5) bodipy dyes being synthesised. Chapter 3 subsequently investigates the relationship between the number and position of fluorine atoms on the aryl moiety, and the resultant photophysical measurements. High fluorescence quantum yields were observed with ortho-substitution of fluorine atoms, a trend that was mirrored with the fluorescence lifetime. Mono-ortho fluorine substitution iii of the aryl group was also found to make the bodipy prochiral pathing the way towards axially chiral bodipy compounds. Chapter 4 follows on from chapter 4 by taking prochiral bodipy compounds to there chiral conclusion. In this chapter several synthetic approaches towards axially chiral (AxC) bodipy compounds are discussed. Included in these synthetic approaches is a completely novel route towards asymmetric bodipy cores thus AxC-bodipy compounds. This chapter represents the first examples of AxC bodipy compounds to exist with future developments in the field aimed at enhanced fluorescence sensing in chiral media and facile enantiomeric determination via circularly-polarised fluorescence measurements. Chapter 5 is an in-depth experimental section where the synthesis and characterisation of each compound is detailed. Also provided are the details for each chemical used, purification and drying methods for each solvent used and techniques used for proper characterisation of all of the compounds.
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Lui, Chih-Hung. "Molecular design and synthesis of coumarin fluorescent dyes." Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/572.
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Pauff, Steven M. "Advancements in the Synthesis and Application of Near-Infrared Imaging Reagents: A Dissertation." eScholarship@UMMS, 2015. https://escholarship.umassmed.edu/gsbs_diss/751.
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Fluorescence-based imaging techniques provide a simple, highly sensitive method of studying live cells and whole organisms in real time. Without question, fluorophores such as GFP, fluorescein, and rhodamines have contributed vastly to our understanding of both cell biology and biochemistry. However, most of the fluorescent molecules currently utilized suffer from one major drawback, the use of visible light. Due to cellular autofluorescence and the absorbance of incident light by cellular components, fluorescence imaging with visible wavelength fluorophores often results in high background noise and thus a low signal-to-noise ratio. Fortunately, this situation can be ameliorated by altering the wavelength of light used during imaging. Near-infrared (NIR) light (650-900 nm) is poorly absorbed by cells; therefore, fluorophores excited by this light provide a high signal-to-noise ratio and low background in cellular systems. While these properties make NIR fluorophores ideal for cellular imaging, most currently available NIR molecules cannot be used in live cells. The first half of this thesis addresses the synthetic difficulties associated with preparing NIR fluorophores that can be used within living systems. Small molecule NIR fluorophores are inherently hydrophobic which makes them unsuitable for use in the aqueous environment of the cell. Water-solubility is imparted to these dyes through highly polar sulfonates, which subsequently prevents the dyes from entering the cell. The novel work presented here details vii synthetic routes to aid in the development of sulfonated NIR fluorophores, which can be delivered into live cells through the inclusion of an esterase-labile sulfonate protecting group. Application of these synthetic techniques should allow for the development of novel NIR fluorophores with intracellular applications. The second half of this thesis addresses the need for novel NIR imaging reagents. Although several classes of NIR scaffolds do exist, most NIR probes are derivatives of a single class, heptamethine indocyanines. The work described here increases this palette by displaying the ability of NIR oxazines to function as an imaging reagent in live cells and in vivo and as a molecular sensor of biologically-relevant environmental conditions. Combined, the work contained herein has the capacity to not only advance the current NIR toolkit, but to expand it so that fluorescence imaging can move out of the dark and into the NIR light.
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Pauff, Steven M. "Advancements in the Synthesis and Application of Near-Infrared Imaging Reagents: A Dissertation." eScholarship@UMMS, 2001. http://escholarship.umassmed.edu/gsbs_diss/751.
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Fluorescence-based imaging techniques provide a simple, highly sensitive method of studying live cells and whole organisms in real time. Without question, fluorophores such as GFP, fluorescein, and rhodamines have contributed vastly to our understanding of both cell biology and biochemistry. However, most of the fluorescent molecules currently utilized suffer from one major drawback, the use of visible light. Due to cellular autofluorescence and the absorbance of incident light by cellular components, fluorescence imaging with visible wavelength fluorophores often results in high background noise and thus a low signal-to-noise ratio. Fortunately, this situation can be ameliorated by altering the wavelength of light used during imaging. Near-infrared (NIR) light (650-900 nm) is poorly absorbed by cells; therefore, fluorophores excited by this light provide a high signal-to-noise ratio and low background in cellular systems. While these properties make NIR fluorophores ideal for cellular imaging, most currently available NIR molecules cannot be used in live cells. The first half of this thesis addresses the synthetic difficulties associated with preparing NIR fluorophores that can be used within living systems. Small molecule NIR fluorophores are inherently hydrophobic which makes them unsuitable for use in the aqueous environment of the cell. Water-solubility is imparted to these dyes through highly polar sulfonates, which subsequently prevents the dyes from entering the cell. The novel work presented here details vii synthetic routes to aid in the development of sulfonated NIR fluorophores, which can be delivered into live cells through the inclusion of an esterase-labile sulfonate protecting group. Application of these synthetic techniques should allow for the development of novel NIR fluorophores with intracellular applications. The second half of this thesis addresses the need for novel NIR imaging reagents. Although several classes of NIR scaffolds do exist, most NIR probes are derivatives of a single class, heptamethine indocyanines. The work described here increases this palette by displaying the ability of NIR oxazines to function as an imaging reagent in live cells and in vivo and as a molecular sensor of biologically-relevant environmental conditions. Combined, the work contained herein has the capacity to not only advance the current NIR toolkit, but to expand it so that fluorescence imaging can move out of the dark and into the NIR light.
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Barucha-Kraszewska, Justyna. "Experimental and stimulation analyses of fluorescent solvent relaxation process in biomembranes : Inflence of ions and molecular interpretation of the dye dynamics." Thesis, Besançon, 2012. http://www.theses.fr/2012BESA3010/document.
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De nombreux processus biologiques liés aux membranes cellulaires lipidiques sont encore très mal connus. La présence d'eau et d'ions à l'interface influence les propriétés structurelles et dynamiques de la bicouche lipidique. Les techniques de fluorescence sont très utiles pour étudier les membranes en raison de la grande sensibilité des sondes à leur environnement. Nous avons utilisé la technique de relaxation de solvant (SR) pour explorer l'hydratation et la mobilité de l'eau. Nous avons également réalisé des calculs quantiques (QM) et des dynamiques moléculaires (DM) pour étayer nos expériences. Les résultats SR montrent qu'un petit cation (Na+) est très attiré par la membrane et augmente sa rigidité à l'opposé des cations (NH4+, Cs+) plus gros. Les anions (CI04-, SCN-) s'adsorbent à l'interface plus facilement que Cl-. Ces anions changent la mobilité et l'hydratation des têtes polaires des lipides de la bicouche. Les études SR de la zone hydrophobe de la membrane montrent que les processus de relaxation sont ici très complexes. lis reflètent des processus rapides intramoléculaire (relaxation de torsion, transferts de charge) et des processus intermoléculaires lents. Les calculs QM ont permis de créer les champs de force de trois sondes fluorescentes (Prodan, Laurdan et C-laurdan). Les simulations DM ont permis de déterminer les positions des sondes dans une membrane DOPC. La modélisation reproduit correctement les résultats SR, en particulier les temps de relaxation : de l'ordre de la ps en solvant aqueux et de la ns dans la membrane. Les simulations MD sont complémentaires des méthodes SR et permettent de surveiller le comportement de molécules uniquesMany biologically important processes and phcnomena in lipid membranes are still not fully understood. The presence of ions and water molœules has a significant influence on the structural and dynamical properties of lipid bilayers. Fluorescent techniques are versatile tools for studying the lipid membranes, because the fluorescence emission is strongly sensitive to dye environment. We have conducted fluorescent solvent relaxation (SR) experiments to explore the hydration and mobility properties in lipid membranes in the presence of different chaotropic ions. We have also carried out Quantum Mechanical (QM) calculations and Molecular Dynamics (MD) simulations for supporting the SR experiments. SR experiments show that small cation (Na+) is attracted to the membrane and increases rigidity ofbilayer, while larger cations (NH/, Cs+) should not. Large anions (CI04·, SCN') adsorl, at the membrane interface more easily than smaller ones (Cl') and significantly change tl!e mobility and hydration of the headgroup region oflipid bilayer. SR study ofhydrophobic part of the membrane show that SR processes are complex there and reflect botl!: faster, intramolecular (torsional relaxation or fonnation of charge transfer state) and slower, intermolecular (SR) relaxation processes. QM calculatiom were used to create force-field for three fluorescent dyes (Prodan, Laurdan and C-laurdan). MD simulations allow detennining position of the dye in the lipid membrane in the ground state and after excitation and reproduce correctly SR timescale- ps in water and ns in the membrane. MD simulations extend the capabilities of SR method and allow observing the behaviour of individual molecules
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Norouzi, Neil. "Synthesis and application of novel near infrared cyanine dyes and optical imaging agents." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/10002.
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The use of fluorescent imaging probes for the real time detection of cellular malfunctions, such as enzyme over expression has shown promise. Fluorescent dyes with absorption and emission values below 600 nm are limited in their in vivo applications due to high background auto-fluorescence and low resolution images. Employing near infrared (NIR) fluorophores such as cyanine dyes can overcome this disadvantage. Cyanine dyes can be synthesised using solution or solid-phase techniques with the use of solution phase chemistry allowing for larger scale and higher yielding reactions. Utilising a selection of functional groups and varying polymethine chain lengths a cyanine dye library with tuneable absorption and emission wavelengths was synthesised. This thesis gives the first detailed examples of how modifications on heptamethine cyanine dyes alter their cellular uptake and cellular toxicity. Furthermore, a NIR fluorescent microsphere is reported as well as NIR functionalised microspheres with the ability to be tracked within cells. Additional lines of work involved the synthesis of a fluorescent sensor for the visualisation of bacteria. Aminopeptidases are present within the peptidoglycan cell wall of Gram negative bacteria and therefore can be targeted for real time detection of bacteria to aid in the detection of infectious diseases. A coumarin based probe is reported which detects aminopeptidase in gram negative bacteria in vitro.
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Rodrigues, Célia Luiza de Lima. "Avaliação da coleta de sangue em papel de filtro para diagnóstico molecular da dengue." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/5/5134/tde-23112010-174300/.
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O diagnóstico rotineiro da dengue é realizado com amostra de sangue dos casos suspeitos. A coleta tradicional de sangue (por punção venosa) é um procedimento que dificulta a realização de exames e pesquisas por ser um procedimento invasivo que nem sempre é prático para crianças e bebês, requer pessoal especializado e necessita de um local para armazenamento da amostra sob refrigeração ou congelamento. O propósito deste estudo foi coletar amostras por punção digital com uma nova tecnologia (FTA Card) e compará-la com amostras coletadas por punção venosa, avaliando-as através de uma técnica molecular de PCR em tempo real. Sendo o PCR em Tempo Real a técnica molecular atualmente disponível de maior rapidez, sensibilidade e especificidade, padronizamos uma metodologia de passo único de PCR em Tempo Real com SYBR green baseando-se na região 3 não codificante do vírus e utilizando primers degenerados, capazes de detectar os quatro sorotipos de uma só vez. A avaliação das técnicas de coleta e amplificação foram feitas com amostras suspeitas de dengue, obtidas em Goiânia durante surto ocorrido no ano de 2008. O limite de detecção da reação padronizada no presente estudo foi de aproximadamente 100 cópias/ml e uma especificidade de 100%. Para tipagem das amostras positivas a técnica empregada foi o PCR multipex. Dentre as 89 amostras coletadas 60 (67%) foram positivas para àquelas coletadas por punção venosa e 14 (16%) para àquelas coletadas por punção digital. Dentre as 89 amostras para o PCR em Tempo Real, apenas 29 (32%), foram tipadas pelo método de PCR multiplex, sendo 3 casos do vírus da dengue 1 (10%), 16 casos do vírus da dengue 2 (55%), e 10 casos do vírus da dengue 3 (35%). Descritores: Dengue/diagnóstico, coleta de amostras sanguíneas, reação em cadeia da polimerase, corantes fluorescentesThe collection by venipuncture is a procedure that is difficult to carry out in diagnosis and research because it is an invasive procedure that is not always practical for children and babies , requires specialized staff, needs a place to store the sample under refrigeration or forzen, This study aimed to collect samples by fingerstick puncture with a new technology named FTA card and compare it with samples collected by venipuncture, using a realtime PCR to evaluate if FTA card collection would have a similar performance to standard blood sampling. Towards that, we obtained viral load values in order to estimate the differences not only qualitatively (e.g. pos or neg) but also in numbers.. We used an one-step SYBR Green I Real-Time PCR based on the region 3 \'noncoding virus using degenerate primers which was able to detected all four serotypes of dengue virus. Among the 89 samples collected 60 (67%) were positive for those collected by venipuncture and 14 (16%) to those collected by fingerstick, Only 29 (32%) were possible to be typed by PCR multiplex. Three cases were dengue virus 1 (10%), 16 cases were dengue virus 2 (55%) and 10 cases were dengue virus 3 (35%). The limit of detection obtained was approximately 100 copies / ml and aspecificity of 100% was observed. Keywords: Dengue / diagnosis, collection of blood samples, polymerase chain reaction, fluorescent dyes
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Baier, Moritz C. [Verfasser]. "Living Polymerization to Ultra-High Molecular Weight and Dye-Labeled Polyethylene for Single-Molecule Fluorescence Microscopy and Reactor Blends / Moritz C. Baier." Konstanz : Bibliothek der Universität Konstanz, 2016. http://d-nb.info/1173616454/34.
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Islam, Mohammed Saiful. "Molecular design and synthesis of high performance fluorescent dyes for textile applications." Thesis, Heriot-Watt University, 2007. http://hdl.handle.net/10399/2081.
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Лопаткін, Юрій Михайлович, Юрий Михайлович Лопаткин, Yurii Mykhailovych Lopatkin, Ю. О. Шевченко, and П. О. Кондратенко. "Застосування теоретико-групового аналізу для дослідження флуоресценції поліметинових барвників." Thesis, Сумський державний університет, 2018. http://essuir.sumdu.edu.ua/handle/123456789/67903.
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Для виявлення природи флуоресценції барвника при переходах з вищих збуджених станів в дослідженнях енергетичної структури молекул використовувався теоретико-груповий аналіз. Катіони поліметинових барвників (ПМБ) в транс-конфігурації описуються групою симетрії C2v.
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Pan, Chung-Min. "Molecular design and synthesis of benzoxazinone-based fluorescent dyes for potential biological applications." Thesis, Heriot-Watt University, 2008. http://hdl.handle.net/10399/2163.
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The principal aims of this project are to develop an understanding of colour and constitution relationships and the factors which influence the fluorescence properties in benzoxazinone-based fluorescent dyes, aza analogues of coumarin dyes, to explore the synthesis of a range of these benzoxazinone-based fluorescent dyes and to investigate their UV/visible and fluorescent spectral properties. A particular focus of this investigation was optimized of the synthesis of the dyes and the effect of solvents and other environmental influences on the electronic absorption and emission spectra of the dyes which might be usefully explored to give biological probe molecules. Molecular modeling studies using the CAChe system (AMI, MM2 PM3, ZINDO calculations) and PPP-MO calculations were used to investigate relationships between the chemical structure, spectral properties and technical performance. Reasonable spectral correlations were found using PPP-MO calculations to predict the colour of the benzoxazinone dyes. Weak solid-state fluorescence was observed under UV-light for the benzoxazinone dyes. This interesting feature was investigated in two cases by x-ray crystallography to explore the reasons for this observation. A test for cytotoxicity was carried out on benzoxazinone and coumarin dyes by the ISO 10993-5 method, which showed slight toxicity for the dyes. On the basis of the results of the investigation it was concluded that the benzoxazinone dyes have potential as probe molecules for biological application. Textile dyeing procedures using the dyes as disperse dyes for polyester were optimized. Colour measurement and assessment of fastness properties were carried out on the dyed fabrics.
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Jakeway, Stephen Christopher. "Evaluation of some fluorescent dyes and molecular tethers for a fibre optic DNA biosensor." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0004/MQ45514.pdf.
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Kirstein, Johanna, Christophe Jung, Christian Hellriegel, and Christoph Bräuchle. "Single molecule spectroscopy: translational and rotational diffusion of single fluorescent dyes in nano-structured porous materials." Diffusion fundamentals 2 (2005) 94, S. 1-2, 2005. https://ul.qucosa.de/id/qucosa%3A14431.
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Semyonov, Alexander N. "Design, Synthesis and Characterization of Fluorescent Dyes and Liquid Crystal Semiconductors." Kent State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=kent1153556141.
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Лопаткін, Юрій Михайлович, Юрий Михайлович Лопаткин, Yurii Mykhailovych Lopatkin, Д. О. Белоус, and П. О. Кондратенко. "Дослідження природи аномальної флуоресценції поліметинових барвників." Thesis, Сумський державний університет, 2018. http://essuir.sumdu.edu.ua/handle/123456789/67730.
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Довгий час вважали, що азулен − єдина сполука з аномальною флуоресценцією, смуга якої в спектрі випромінювання лежить вище першої смуги поглинання молекули. Однак, синтез нових барвників для створення лазерів і їх дослідження показали, що азулен в цьому плані далеко не унікальний. Одним з таких нових класів барвників є поліметинові барвники (ПМБ).
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Härtling, Thomas, Phillip Olk, Marc Tobias Wenzel, and Lukas M. Eng. "Metallpartikel erhellen die Nanowelt: Optische Nahfeldmikroskopie an organischen Fluoreszenzmolekülen." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1188474281833-71852.
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Modern optical microscopy is gaining deeper and deeper insight into the nanoworld. Conventional microscopy faces restrictions by both the diffraction limit and its sensitivity concerning the low intensities of nanoscale light sources. To be able to circumvent these drawbacks, scanning near-field optical microscopy (SNOM) has been implemented at the Institute of Applied Photophysics at the TU Dresden by applying optically active scanning probes in order to constitute interfaces between the macroscopic and the nanoscopic world. New probes functionalised with metal nanoparticles can resolve structures which are unreachable by traditional methods (~ 50 nm). Our work has led to inexpensive and fast fabrication of such probes allowing an unprecedented views of the nanoworldDie moderne optische Mikroskopie erlaubt es, der Nanowelt immer neue spannende Erkenntnisse zu entlocken. Jedoch ist die herkömmliche Lichtmikroskopie in ihrer Auflösung begrenzt und im Hinblick auf die geringe Intensität nanoskopischer Lichtquellen häufig nicht empfindlich genug. Um diese Probleme zu umgehen, wird am Institut für Angewandte Photophysik (IAPP) der TU Dresden die sogenannte optische Nahfeldmikroskopie eingesetzt. Hierbei dienen optisch aktive Sonden als Schnittstelle zwischen makroskopischer und nanoskopischer Welt. Diese am IAPP entwickelten neuartigen Sonden sind mit metallischen Nanopartikeln besetzt. Das Nahfeldmikroskop erlangt mit derartigen Sonden ein Auflösungsvermögen, welches weit jenseits der Möglichkeiten konventioneller Mikroskope liegt. Die Sonden können einfach und schnell hergestellt werden und erlauben der Nahfeldmikroskopie bisher unerreichte Einblicke in die Nanowelt
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Bryant, Jason. "Polarised photoselection and molecular dynamics in liquid crystals and proteins." Thesis, University of Essex, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313097.
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Peck, John Patrick. "Molecular measurement through the use of fluorescent dyes : with a special emphasis on the chemical physics of solvatochromic dyes immobilised in polymers." Thesis, London Metropolitan University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391912.
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Smortsova, Yevheniia. "Dye sensitized solar cells efficiency improvement : optimization of the electrolyte using ionic liquids/molecular solvents mixture and study of the photodynamic properties of organic indolinic derivative dyes." Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1R061/document.
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Parmi les énergies renouvelables, l’énergie solaire est la plus puissante. L’élément clé des DSSCs est le photosensibiliseur, par lequel la génération de photocourant est possible. L’autre élément important est l’électrolyte. Les liquides ioniques (Ils) sont utilisés en tant qu’électrolytes dans les DSSCs du fait de leurs propriétés chimiques: pression de vapeur basse, haute résistance thermique et chimique, polarité et phase modulables, etc. L’objectif de cette thèse est de comprendre les processus photophysiques dans les colorants dérivés d’indolines dans les solvants moléculaires (MS) et les mélanges IL/MS. L’influence du solvant sur les propriétés spectroscopiques de D131, D102, D149 and D205 est d’abord étudiée par spectroscopie stationnaire d’absorption et de fluorescence. Ensuite, la spectroscopie résolue en temps est employée pour étudier leur photophysique et sa dépendance au solvant. Ces expériences ont permis de démontrer l’influence des paramètres d'aptitude de donneur de liaison hydrogène et d'accepteur de liaison hydrogène des solvants. Le rôle majeur de la dynamique de solvatation dans la dynamique des états excités de ces colorants a été montré. Ce phénomène a été suivi dans les mélanges IL/MS en utilisant une sonde fluorescente classique, C153, et des techniques de fluorescence résolues en temps et de dynamique moléculaire. Les réponses de solvatation multi-régimes de ces mélanges sont dirigées par le renforcement de la liaison hydrogène entre la sonde et les composants des mélanges. Les résultats de cette these apportent beaucoup à la compréhension des processus photophysiques fondamentaux régissant les sensibiliseurs et les électrolytes dans les DSSCsAmong all the renewable energy sources, solar energy is the most powerful source far ahead wind or geothermal energies. The first key component of DSSCs is the photosensitizer. It is through this component that the most important steps of photocurrent generation are possible. On the other hand, ionic liquids (ILs) have been proposed as electrolyte for DSSCs due to their peculiar properties: low vapor pressure, high thermal and chemical robustness, tunability of polarity and phase behaviour etc. The objective of this thesis was to get an understanding of the photophysics in the indoline derivated dyes in molecular solvents (MS) and in the IL/MS mixtures. Firstly, the solvent dependence of the spectroscopic properties of D131, D102, D149 and D205 was studied by the steady-state UV-Vis absorption and fluorescence spectroscopy. Then, time-resolved spectroscopy was used to elucidate their photophysics and its solvent dependence. These experiments helped to discern the influence of the hydrogen bond donor and acceptor abilities of the solvent. The solvation dynamics was shown to play a major role in the excited state dynamics of these dyes. This process in IL/MS mixtures was elucidated using the classic fluorescent probe C153 by the means of time-resolved spectroscopy and MD simulations. The complex multi-regime solvation response in these systems was shown to be shaped by the strengthening of the hydrogen bonding between the probe and the mixture components. The results of this thesis work contribute to the fundamental understanding of the photodynamics of the sensitizer and the response of the electrolyte used in the DSSCs
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Bernhard, Claire. "Synthèse d'agents chélatants bifonctionnels macrocycliques pour le marquage de molécules biologiques par des métaux : application en imagerie médicale." Thesis, Dijon, 2011. http://www.theses.fr/2011DIJOS024/document.
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L’imagerie moléculaire est devenue incontournable pour le diagnostic et le traitement de cancers. Cette discipline regroupe un ensemble de techniques telles que la tomodensitométrie (CT), l’Imagerie par Résonance Magnétique (IRM), l’imagerie optique ou encore l’imagerie nucléaire (tomographie par émission de positons TEP, tomographie d’émission monophotonique TEMP). Chacune de ces techniques possède ses propres avantages et inconvénients et ne peut apporter à elle seule des informations anatomiques et fonctionnelles suffisantes. Les travaux actuels sont portés sur la conception de systèmes dits multimodaux afin de combiner les avantages de différentes techniques, voire de bénéficier d’un effet synergique. De par leur sensibilité comparable et leur complémentarité, coupler l’imagerie nucléaire à l’imagerie optique devient alors avantageux. La conception des systèmes monomoléculaires (MOMIA) contenant deux fonctions détectables par imagerie nucléaire (complexe de radiométaux) et imagerie optique (sonde fluorescente) nécessite en amont la mise au point d’outils de synthèses performants. La première partie de ce travail de thèse est consacrée à la synthèse d’agents chélatants bifonctionnels à base de polyamines macrocycliques, destinés à une utilisation en imagerie médicale. Ces agents doivent présenter d’excellentes propriétés de coordination vis-à-vis du métal visé, et posséder une fonction de greffage pour assurer le couplage avec une biomolécule vectrice. L’accès à de tels systèmes a nécessité le développement d’outils de synthèse efficaces de précurseurs macrocycliques dérivés du cyclène et du 13aneN4. L’introduction sélective de diverses fonctions de greffage visant principalement les résidus de type lysine a permis la préparation de plusieurs familles de composés, dont certains ont pu être « bioconjugués» à des peptides ou anticorps au sein du laboratoire ou dans le cadre de diverses collaborations. Plus particulièrement, la facilité d’utilisation du système « DOTAGA anhydride » a permis l’introduction aisée d’unités DOTA sur des nanoparticules ou des anticorps monoclonaux. Egalement, l’introduction d’une fonction alcyne a permis l’accès à de nouvelles briques moléculaires préparées par « click chemistry ». Dans une seconde partie sont présentés les travaux relatifs à la synthèse d’agents bimodaux originaux. Pour accéder à de tels systèmes, l’introduction d’un fluorophore de la famille des bodipys a été envisagée. L’absence de travaux antérieurs relatifs au couplage d’une polyamine cyclique et une entité bodipy a nécessité la préparation préalable d’un système modèle « DOTA bodipy », permettant de s’assurer par des études photophysiques que la présence des complexes métalliques macrocycliques ne va pas, ou peu, interférer avec les propriétés de fluorescence du bodipy. L’utilisation d’un espaceur « acide aminé » a alors permis d’accéder à de nouveaux bodipys porteurs de deux groupes fonctionnels en position méso. La fonctionnalisation a posteriori de ces briques de construction a permis l’introduction en dernier lieu d’unités macrocycliques N- et/ou C- fonctionnalisés. La préparation de système émettant dans le proche I.R. a été également envisagéeMolecular imaging became a major tool for the diagnosis and the treatment of cancers. This research field includes different techniques, such as Tomography (CT), Magnetic Resonance Imaging (MRI), Optical Imaging or nuclear Imaging (PET Positron Emission Tomography, SPECT Single Photon Emission Computed Tomography). Each imaging modality has its own strengths and weaknesses, and thus, combining different and complementary systems can overcome inherent limitations associated with any one individual techniques and improve the accuracy of disease diagnosis and enhancing patient management. In particular dual-modality Optical/Nuclear imaging may find important preclinical and clinical applications. One possible approach seeks to fuse the two imaging systems into one molecule (MonOmolecular Multimodality Imaging Agent [MOMIA]) in order to ensure the same biodistribution of the two probes. Our strategy consists in combining a DOTA-like compound allowing complexation of radiometal for nuclear imaging (SPECT or PET) with a bodipy moiety, valuable probe those fluorescent properties can be finely adjusted. The first part of this work is dedicated to the synthesis of bifunctional chelating agents based on macrocyclic polyamines for medical imaging application. These compounds must show excellent coordination properties towards the aimed radiometal and possess a grafting function to allow the coupling with a biomolecule. Powerful and general routes for the synthesis of a wide range of N- and C-functionalized macrocycles derived from cyclen and 13aneN4 are described, which enable to access to a wide range of new BFCs by introduction of different functional groups reactive towards primary amines, such as carboxylic acid, isothiocyanate or anhydride function. Some compounds were conjugated to different biomolecules, such as peptides or antibodies. Morever, the introduction of an alkyne function yields a novel family of bifunctional agents allowing chemoselective attachment to functionalized biomolecules or to modified amino acids using « click chemistry ». In a second part, we focused on the introduction of a bodipy moeity to obtain new bimodal agents for dual Optical/Nuclear imaging. Interestingly, the attachment of the polyaminocarboxylate (DOTA derivative) to the bodipy makes it soluble in water and complexation of different metal cations of interest in the macrocyclic cavity does not significantly alter the luminescence properties of the whole system. In addition, the functionalization of the meso position by using an appropriate linker between the bodipy and DOTA-like units, i.e. a 4-nitrophenylalanine derivative, could provide a new bimodal tag for labeling antibodies or peptides. Optimisation of the second generation bodipy-DOTA, i.e. derivatization reaction to reach the near-IR range or introduction of C-functionalised macrocycles was also investigated
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Sjöqvist, Jonas. "Light interactions in flexible conjugated dyes." Doctoral thesis, Linköpings universitet, Beräkningsfysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-109011.
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In this thesis methodological developments have been made for the description of flexible conjugated dyes in room temperature spectrum calculations. The methods in question target increased accuracy and efficiency by combining classical molecular dynamics (MD) simulations with time-dependent response theory spectrum calculations. For absorption and fluorescence spectroscopies a form of conformational averaging is used, where the final spectrum is obtained as an average of spectra calculated for geometries extracted from ground and excited state MD simulations. For infrared and Raman spectroscopies averaged spectra are calculated based on individual spectra, obtained for zero-temperature optimized molecular structures, weighted by conformational statistics from MD trajectories. Statistics for structural properties are also used in both cases to gain additional information about the systems, allowing more efficient utilization of computational resources. As it is essential that the molecular mechanics description of the system is highly accurate for methods of this nature to be effective, high quality force field parameters have been derived, describing the molecules of interest in either the MM3 or CHARMM force fields. These methods have been employed in the study of three systems. The first is a platinum(II) actylide chromophore used in optical power limiting materials, for which a ultraviolet/visible absorption spectrum has been calculated. The second is a family of molecular probes called luminescent conjugated oligothiophenes, used to detect and characterize amyloid proteins, for which both absorption and fluorescence spectra have been calculated. Finally, infrared and Raman spectra have been calculated for a group of branched oligothiophenes used in organic solar cells. In addition, solvation effects have been studied for conjugated poly\-eletrolytes in water, resulting in the development of two solvation models suitable for this class of molecules. The first uses a quantum meachanics/molecular mechanics (QM/MM) description, in which the solute mole\-cule is described using accurate quantum mechanical methods while the surrounding water molecules are described using point charges and polarizable point dipoles. The second discards the water entirely and removes the ionic groups of the solute. The QM/MM model provides highly accurate results while the cut-down model gives results of slightly lower quality but at a much reduced computational cost. Finally, a study of protein-dye interactions has been performed, with the goal of explaining changes in the luminescence properties of the LCO chromophores when in the presence of amyloid proteins. Results were less than conclusive.
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Ftouni, Hussein. "Ingénierie moléculaire de fluorophores absorbants biphotonique pour des applications biologiques." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00809524.
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La fluorescence excitée à deux photons est actuellement largement utilisée pour l'imagerie de tissus biologiques, mais la faible sensibilité des fluorophores utilisés en microscopie confocale (excitation à un photon) à une excitation à deux photons (ADP) rend nécessaire la conception et la synthèse de nouveaux fluorophores spécifiques pour la microscopie de fluorescence par excitation bi-photonique (MFEB). Mon travail de thèse a ainsi porté sur l'ingénierie moléculaire (conception, synthèse et caractérisations) de nouveaux fluorophores pour la MFEB. Nous nous sommes particulièrement intéressés à des systèmes unidimensionnels (1D) de petite taille comportant des systèmes π étendus autour d'un cœur rigide (dicétopyrrolopyrrole ou DPP) et entourés de différents systèmes électro-actifs. Nous avons modifié par la suite les fluorophores précédents de manière à pouvoir les conjuguer à des molécules d'intérêt biologique, comme des protéines. Ces fluorophores bio-conjugables ont été greffés sur un peptide du virus HIV étudié au laboratoire : TAT (Trans-Activator of Transcription). L'imagerie par microscopie biphotonique a été effectuée avec succès sur des cellules HeLa. Nous nous sommes ensuite tourné vers la mise au point de nouvelles sondes multimodales pour associer la MEBP à une autre modalité d'imagerie : la résonance magnétique nucléaire et la microscopie électronique (imagerie corrélative). Pour ce faire nous avons développé des colorants fluorescents par excitation bi-photonique comportant une entité paramagnétique ou dense aux électrons (nanoparticules de magnétite, ion gadolinium III ou atomes lourds comme le platine et l'or).
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Тарабара, У. К. "Спектроскопічне та молекулярно-динамічне дослідження фібрилярних агрегатів білків." Thesis, Харьков: ХНУ имени В. Н. Каразина, 2021. http://dspace.univer.kharkov.ua/handle/123456789/16388.
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Дисертація на здобуття ступеня доктора філософії за спеціальністю 105 –
Прикладна фізика та наноматеріали (Галузь знань 10 – Природничі
науки)Дисертаційна робота присвячена вирішенню однієї з важливих проблем сучасної фізики біополімерів, пов’язаної із встановленням молекулярних механізмів структурного переходу білків із нативної конформації в агрегований фібрилярний стан. Мета роботи полягала у з’ясуванні закономірностей взаємодії нових флуорохромів з фібрилярними агрегатами білків та визначенні молекулярних детермінантів процесу фібрилізації.
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FESSL, Tomáš. "Single-molecule fluorescence detection in molecular biology." Doctoral thesis, 2012. http://www.nusl.cz/ntk/nusl-151539.
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SMFD techniques offer genuine detection possibilities which are often inaccessible using ensemble methods. This was demonstrated in three projects investigating translocation activity of CHD4 protein, analysis of MS2 phage capsid assembly and in-cell characterization of DNA structure. In other projects, binding interactions between two fluorescent probes and a short oligonucleotide were characterized and all optical depth of focus extended microscope configuration for imaging of individual molecules inside bacterial cells was developed and tested.
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ROMANCOVÁ, Ingrid. "Binding of Cyanine Fluorescent Probes to DNA." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-253031.
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This master thesis is focused on theoretical study of the Cy3 and Cy5 dyes and their interactions with DNA. The main aim was to find the mot populated conformations of the Cy3-DNA and Cy5-DNA complexes. A comparison with the experimental structure was also done and the influence of the cyanine dyes on the conformational changes of the DNA chain was evaluated.
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Schmitt, Alexander [Verfasser]. "Reactive fluorescent dye systems for single-molecule studies / von Alexander Schmitt." 2009. http://d-nb.info/99785281X/34.
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Lin, Yu-Chun, and 林鈺君. "The Study of Fluorescence Quenching of Dye Molecules by Nano Semiconductor Particles." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/45683518676300821457.
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碩士輔仁大學
化學系
92
At present, the solar-cell is in widespread use abroad. Because of the limited source and expensive cost of electric power in Taiwan, we can adopt solar-cell to achieve low cost and to solve energy resource problem. We can optimize the solar-cell performance using the better and cheaper stains and suitable semiconductor materials and implement it in practical. This paper will discuss six dyes, Acridine, Pyrene, Carbazole,α-Carbazole,7-HQ and 7-AI, to be a electric transport layer and four semiconductor materials, Fe2O3,TiO2,CdS and ZnO, to match the hole transport layer in solar-cell. We find the relationship between six dyes and four semiconductors to optimize the solar-cell performance.
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Kuo, Ju-Wen, and 郭汝汶. "Fluorescence of dye molecules on Ag nanostructure on graphene covered Ag pads." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/21158310591478330417.
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碩士國立中正大學
物理學系暨研究所
100
We self-assemble Ag nanoparticles on the top of Ag pads covered with a monolayer graphene as a spacer layer. Ag atoms deposited on top of the graphene layer was isolated from the Ag pad below, and formed Ag nanoparticles during annealing process in ambient environment. We measured the fluorescent intensity from Cy3 dye molecules coated on the sample before and after annealing. We found that the Ag pad becomes nearly invisible in the fluorescent image after annealing.
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Nanthasurasak, P. "Electrophoretic separations of small molecules in low diffusion environment." Thesis, 2019. https://eprints.utas.edu.au/34063/1/Nanthasurasak_whole_thesis.pdf.
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Portable analytical devices have been sought after heavily to support clinical diagnostics in lack-of-resource areas where access of advanced medical devices and specialists are restricted. Even though there are many commercially available portable Point-of-care (POC) devices allowing easy and rapid self-diagnostic, these POC were developed for generic infectious diseases such as diabetes or HIV and are not yet made for many common life-threatening disorders. In these cases, portable sample collection devices, such as Guthrie card, are employed for collection of biological samples including blood, urine, or saliva from patients off-hospital then the samples are sent to the centralized laboratory for analysis. However, several post-processing steps of the collected samples (i.e. extraction) upon arrival are required prior to the analysis and these are time-consuming steps that delay the turn-around-time of the result.
Electrophoresis, separation of molecules under application of electric field, is a powerful analytical and sample preparation technique mostly utilized in clinical diagnostics to isolate components in samples ready for analysis. Recently, there has been a large number of developments with electrophoresis into miniaturized formats; however, they are not yet fully integrated with a high voltage power supply and liquid electrolytes are needed to perform separation making it unsuitable as portable diagnostic device. In attempt to bring forward a practical platform for clinical sample collection and sample preparation, the main goal of this thesis is to create a portable electrophoretic platform capable of performing solvent-free electrophoresis under relatively low voltage addressing issues found in conventional clinical diagnostics and electrophoresis. In this research, a polymer inclusion membrane (PIM) embedded with a carrier was investigated as a separation medium for electrophoresis for the first time.
In chapter 2, PIM casting, dimension design, and electrophoresis apparatus are reported. A thin PIM was employed in this research in a lateral strip and electromigration studies were performed of fluorescent dyes with different charges including Coumarin 334, Fluorescein, and Rhodamine 6G (R6G) as neutral, anionic, and cationic analytes, respectively. The electromigration was monitored and recorded using a portable fluorescence microscope. Three main components of PIM – cellulose triacetate (CTA) as polymer base, 2-nitrophenyl octyl ether (2-NPOE) as plasticizer, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][NTf\(_2\)]) as carrier – were optimized as the ratios were found to impact on the migration distance and the spot shape of the dyes. Under a voltage of 2000 V (500 V/cm), only migration of cationic R6G was observed in this PIM leading to further investigation of electrophoresis of several cationic dyes. Successful electrophoretic separation of cationic dyes then allowed the electrophoretic mobilities and diffusion constants to be estimated for each species. Additionally, physical characterization of the PIM and possible mechanism of electromigration were also elucidated.
Chapter 3 focuses on the potential of the PIM-based electrophoretic platform being useful in clinical application in the form of a portable electrokinetic device performing separation, as sample preparation, at low voltage while being transited to a central laboratory eliminating additional steps needed upon arrival. A positively charged alkaloid, Berberine chloride (BC), was used as a model analyte resembling small molecule pharmaceuticals spiked into the whole blood sample. Laboratory-based experiments revealed electromigration of BC but not dried drop of blood resulting in successful separation of BC from the blood matrix. To pursue the concept of in-transit separation, the PIM strip was fully assembled into a pocket-sized device with plastic housing equipped with two commercial batteries generating 6 V/cm (24 V) potential for separation. Separation real-time during transit was demonstrated by sending a portable device containing spiked BC in whole blood via internal mail and the analysis was performed once returned.
To investigate PIM selectivity towards anions, a different ionic liquid, Aliquat\(^®\)336, was investigated as a carrier in chapter 4. It was found that not only electromigration of anionic species was observed but neutral molecules also migrated presumably from heteroconjugation. The tunability of the PIM was further investigate using several cationic surfactants with a similar chemical structure to Aliquat®336, with different number of carbon units, number of chains, chain length and counter anions, as carriers and their influence on electromigration and selectivity of dyes were investigated. While most of the cationic surfactants were found to have similar selectivity towards anionic molecules to Aliquat\(^®\)336, anionic surfactants investigated revealed selectivity towards cationic species similar to that observed with [EMIM][NTf\(_2\)].
In the last chapter, the possibility of integrating Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) for detection of in-transit electrokinetic separations was explored. The experiment was performed to extend the applicability to non-coloured analytes as well as demonstrating for more powerful practical workflow allowing upon-arrival detection without additional labelling or derivatizing of analytes. PIM after in-transit separation was detached and taped on conductive Indium Tin oxide glass slide before being spray-coated with matrix α-Cyano-4-hydroxycinnamic acid (4-HCCA) and scanned using MALDI imaging. Colour intensity profile and distribution of BC molecules after electrophoretic separation from whole blood sample were graphically displayed in such case where the electrophoretic migration distance was unknown. The results showed promising potential for MALDI-TOF to be employed as detection method for in-transit electrokinetic platform concept where non-coloured analytes can be analyzed.
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Wu, Ying Yi, and 吳盈漪. "Application of Disassembly-Emission Dye and Molecular Rotor in Fluorescence Turn-on Detection of Proteins." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/76809086914101270871.
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碩士國立清華大學
化學系
103
Currently most of the fluorogenic probes are designed for the detection of enzymes which work by converting the non-fluorescence substrate into the fluorescence product via an enzymatic reaction. On the other hand, the design of fluorogenic probes for non-enzymatic proteins remains a great challenge. Herein, we report a general strategy to create near-IR fluorogenic probes, where a small molecule ligand is conjugated to a novel γ-phenyl-substituted Cy5 fluorophore, for the selective detection of proteins through a non-enzymatic process. Detail mechanistic studies reveal that the probes self-assemble to form fluorescence-quenched J-type aggregate. In the presence of target analyte, bright fluorescence in the near-IR region is emitted through the recognition-induced disassembly of the probe aggregate. Based on this design, a fluorogenic probe for hCA II detection was constructed and was applied for the no-wash imaging of tumor cells for the detection of hypoxia-induced cancer-specific biomarker, transmembrane-type carbonic anhydrase IX. We have also created another fluorogenic probe which belongs to a class of fluorescent dyes called molecular rotors for the detection of human serum albumin (HSA), a key indicator for the early diagnosis of renal disease and for the cardiovascular disease in non-diabetic individuals. In aqueous buffer, molecular rotors show extremely weak fluorescence due to the unrestricted torsional rotation. In the presence of target analyte, bright fluorescence can be observed because of restricted torsional rotation. In the presence of albumin, the probe exhibits remarkable 400-fold fluorescence enhancement with high selectivity and sensitivity. The probe was successfully applied in the quantitative detection of urinary albumin.
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Chizhik, Alexey [Verfasser]. "Modifying fluorescence of single quantum emitters : single dye molecules and SiO2 nanoparticles in a tunable subwavelength microcavity / vorgelegt von Alexey Chizhik." 2011. http://d-nb.info/1012634930/34.
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Vaiana, Andrea C. [Verfasser]. "Towards the understanding of fluorescence quenching mechanisms : molecular dynamics simulations of dye-quencher interactions in biomolecular systems / presented by Andrea C. Vaiana." 2004. http://d-nb.info/97034838X/34.
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Novak, Jennifer. "Observation Of Spectral Changes To Trp-214 Residue In Human Serum Albumin Upon Binding With Mangiferin And Near Infrared Dyes." 2015. http://scholarworks.gsu.edu/chemistry_theses/78.
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A novel approach of using near infrared region (NIR) dyes is applied to elucidate the binding interaction between human serum albumin (HSA) and mangiferin (MGF). HSA is a blood carrier protein used for drug delivery, while mangiferin is a natural polyphenol found in mangoes that possesses numerous beneficial health properties. The NIR dyes are used as a probe to investigate MGF binding interaction with HSA via monitoring fluorescence of Trp-214 residue. Molecular modeling is used for docking and semi-empirical analysis. The investigation of the binding interaction between Trp-214 and MGF is significant, for it may offer broader pharmacological insight and applications for the polyphenol. Mangiferin in proposed to bind with a 2:1 stoichiometric ratio with HSA to the Trp-214 residue in subdomain IIA and another possible binding site to be determined in future studies. Spectral changes suggest a stabilized protein conformation upon mangiferin binding with the addition of NIR dye E-06 and MHI-06.
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McCanna, David. "Development of Sensitive In Vitro Assays to Assess the Ocular Toxicity Potential of Chemicals and Ophthalmic Products." Thesis, 2009. http://hdl.handle.net/10012/4338.
Full textAbstract:
The utilization of in vitro tests with a tiered testing strategy for detection of mild ocular irritants can reduce the use of animals for testing, provide mechanistic data on toxic effects, and reduce the uncertainty associated with dose selection for clinical trials. The first section of this thesis describes how in vitro methods can be used to improve the prediction of the toxicity of chemicals and ophthalmic products. The proper utilization of in vitro methods can accurately predict toxic threshold levels and reduce animal use in product development. Sections two, three and four describe the development of new sensitive in vitro methods for predicting ocular toxicity. Maintaining the barrier function of the cornea is critical for the prevention of the penetration of infections microorganisms and irritating chemicals into the eye. Chapter 2 describes the development of a method for assessing the effects of chemicals on tight junctions using a human corneal epithelial and canine kidney epithelial cell line. In Chapter 3 a method that uses a primary organ culture for assessing single instillation and multiple instillation toxic effects is described. The ScanTox system was shown to be an ideal system to monitor the toxic effects over time as multiple readings can be taken of treated bovine lenses using the nondestructive method of assessing for the lens optical quality. Confirmations of toxic effects were made with the utilization of the viability dye alamarBlue. Chapter 4 describes the development of sensitive in vitro assays for detecting ocular toxicity by measuring the effects of chemicals on the mitochondrial integrity of bovine cornea, bovine lens epithelium and corneal epithelial cells, using fluorescent dyes.
The goal of this research was to develop an in vitro test battery that can be used to accurately predict the ocular toxicity of new chemicals and ophthalmic formulations. By comparing the toxicity seen in vivo animals and humans with the toxicity response in these new in vitro methods, it was demonstrated that these in vitro methods can be utilized in a tiered testing strategy in the development of new chemicals and ophthalmic formulations.