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Dissertations / Theses on the topic 'Fluorescence properties'
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Zhou, Xiaobo. "Design, synthesis and sensing properties of chiral amine-based fluorescent probes." HKBU Institutional Repository, 2012. https://repository.hkbu.edu.hk/etd_ra/1442.
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Ferguson, A. J. "Fluorescence properties of diphenylpolyenes in solution." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238201.
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Pauff, James. "Fluorescence properties of metallo-beta-lactamase L1." Miami University Honors Theses / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1111003051.
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Yu, Yanhua. "Synthesis and properties of triazole-containing fluorescent molecules." Thesis, Cachan, Ecole normale supérieure, 2013. http://www.theses.fr/2013DENS0028.
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Cette thèse se concentre sur le design et la synthèse de molécules fluorescentes contenant un motif triazole et un squelette benzothiadiazole (BTD), coumarine, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacène (BODIPY) ou dicyanométhylène-4H-pyran (DCM) par chimie "click" et l’étude de leurs propriétés et applications en biologie et en chimie analytique. Dans le but de synthétiser des peptides fluorescents et d'étudier leurs applications, des acides aminés fluorescents contenant BTD, coumarine et BODIPY ont été préparés par réaction "click", et incorporés dans la somatostatine par synthèse peptidique en phase solide. Les peptides fluorescents synthétisés pourront être utilisés pour le développement d'un test de "binding" des analogues de la somatostatine. Des dérivés de BTD et BODIPY ont également été conçus et synthétisés pour servir de mimes de coudes beta- qui conduisent à des peptides courts qui pourraient être facilement détectés et étudiés en utilisant des techniques de fluorescence. La capacité des composés obtenus à former des liaisons hydrogène intramoléculaires a été étudiée par spectroscopie infrarouge. En outre, une série de macrocycles à base de BODIPY contenant un C-glucopyranoside conjugué ou non à des acides aminés tels que glycine, acid aspartique ou méthionine ont été synthétisés avec succès en utilisant une réaction "click" comme étape de macrocyclisation. Certains des composés synthétisés présentent des propriétés de reconnaissance sélective vers Cu2+, Fe3+, F- et CN- dans l'acétonitrile. Enfin, un nouveau capteur fluorescent, qui est capable de reconnaître les cations et anions d'une manière coopérative, a été conçu et synthétisé par chimie "click". Ce composé est très sensible à des combinaisons de Cu2+, F- et / ou Br- d’une manière séquence- et halogénure-dépendanteThis thesis is focused on the design and synthesis of triazole-containing fluorescent molecules based on benzothiadiazole (BTD), coumarin, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) or dicyanomethylene-4H-pyran (DCM) by “click” chemistry and investigation of their properties and applications in biology and analytical chemistry. In the aim to synthesize fluorescent peptides and investigate their applications, fluorescent amino acids containing BTD, coumarin and BODIPY were prepared by “click” reaction, and incorporated into somatostatin through solid phase peptide synthesis. The resulting fluorescent peptides could be used for the development of a binding assay for somatostatin analogues. BTD and BODIPY derivatives have also been designed and synthesized to act as beta-turn mimics which lead to short conformationally restricted peptides that could be easily detected and studied using fluorescence techniques. The ability of the synthesized compounds to form intramolecular hydrogen bond was studied by infrared spectroscopy. Moreover, a series of BODIPY-based macrocycles containing a C-glucopyranoside conjugated or not with various amino acids such as glycine, aspartic acid or methionine have been successfully synthesized by using “click” reaction as the macrocyclization step. Some of the synthesized compounds exhibited selective recognition properties towards Cu2+, Fe3+, F- and CN- in acetonitrile. Finally, a new fluorescent sensor, which has the ability to recognize cations and anions in a cooperative way, was designed and synthesized by “click” chemistry. This compound was highly sensitive to combinations of Cu2+, F– and/or Br– in a sequence- and halide-dependent way
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Manceau, Mathieu. "Single CdSe/CdS dot-in-rods fluorescence properties." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066362/document.
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Les nanocristaux colloïdaux synthétisés par voie chimique sont des sources prometteuses de lumière non-Classique à température ambiante. Ce travail est consacré à l'étude des propriétés optiques d'un type particulier de nanocristaux colloïdaux, appelé coeur-Bâtonnet, dans lequel un noyau de Seleniure de Cadmium (CdSe) sphérique est entouré d'une coquille de Sulfure de Cadmium (CdS) de forme cylindrique. En étudiant des particules de type coeur-Bâtonnet à température ambiante avec un microscope confocal, une caractérisation complète des propriétés optiques de ces émetteurs est réalisée. Nous étudions d'abord la statistique de clignotement de ces émetteurs. Nous montrons que les émetteurs coeur-Bâtonnet avec des coquilles épaisses se caractérisent par un clignotement réduit sur des échelles de temps courts, inférieurs à quelques millisecondes. Ensuite, une caractérisation détaillée de la statistique de photons des émetteurs coeur-Bâtonnet tenant compte du phénomène de clignotement est réalisée. La polarisation de l'émission est également étudié. Nous montrons que la polarisation d'émission peut être controlée en changeant la géométrie de la structure.Enfin, nous présentons également des expériences de couplage de ces émetteurs avec des dispositifs photoniques. Nous montrons la possibilité d'exciter un émetteur coeur-Bâtonnet en utilisant un nanofil d'oxyde de Zinc (ZnO). Nous montrons aussi que nous sommes en mesure d'orienter efficacement des nanoémetteurs uniques en utilisant la formation controlée de défauts dans des cristaux liquidesWet-Chemically synthesized colloidal nanocrystals are promising room temperature non-Classical light sources. This work is devoted to the study of the optical properties of a particular type of colloidal nanocrystals, called dot-In-Rods, in which a spherical Cadmium Selenide (CdSe) core is surrounded by a rod-Like Cadmium Sulfide (CdS) shell. By studying single dot-In-Rods at room-Temperature with a confocal microscope, a complete characterization of the optical, and especially quantum optical, properties of dot-In-Rods is provided for several geometrical parameters. We first study the blinking statistics of such emitters. We show that dot-In-Rods with thick shells are characterized by a reduced blinking that happens on fast timescales, typically on millisecond timescales. We then go on with a detailed characterization of the photon statistics of dot-In-Rods. A complete description of the photon statistics taking into account the blinking process is realized. The polarization of the emission is also investigated. We show that the emission polarization can be tuned by engineering the geometry. Finally, we also present experiments where we couple dot-In-Rods with various photonic devices. We demonstrate the possibility of excitation of a single emitter using a Zinc Oxyde (ZnO) nanowire. Using defects in liquid crystals, we also show that we are able to efficiently orientate single nanoemitters
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Lutkouskaya, Katsiaryna. "Fluorescence properties of dye-zeolite L nanochannel materials /." [S.l.] : [s.n.], 2007. http://www.zb.unibe.ch/download/eldiss/07lutkouskaya_k.pdf.
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Vall-Llosera, Gemma. "Fluorescence properties of trendy molecules studied with synchrotron radiation /." Stockholm : School of Engineering Sciences, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4148.
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Grazios, Fabio. "Fluorescence properties of single nitrogen-vacancy centre in diamond." Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543481.
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Ismail, G. H. "Studies on the fluorescence and photoyellowing properties of wool." Thesis, City University London, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378863.
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Jazmati, A. K. "Optical properties and laser induced fluorescence from BGO:RE waveguides." Thesis, University of Sussex, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297953.
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Yuan, Dongwu. "The synthesis and fluorescence properties of some substituted naphthalimides." Thesis, University of Central Lancashire, 1994. http://clok.uclan.ac.uk/20016/.
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A number of known and novel naphthalimide derivatives have been synthesised. For many of the known compounds, improvements in their syntheses have been achieved in terms of higher yield and/or milder reaction conditions. Some of the novel compounds have been prepared with the aim of improving the water-solubility of the system by the introduction of substituents containing polar terminal groups and by sulfonation on the naphthalene ring. The sulfonated compounds exhibit quite good watersolubility and the others also show some improvement. Chloroacetyl and maleimido functions have been introduced into naphthalimides as reactive groups for attachment to biological molecules. Some brominated naphthalimides have been prepared for a study of their photochemical properties. The absorption and fluorescence properties of the synthesised naphthalimides have been studied. The maximum absorption wavelengths and extinction coefficients of their ultraviolet/visible spectra and their fluorescence spectra together with quantum yields and lifetimes have been measured for the naphthalimide compounds. The effects of the substituents on the photophysical properties were studied. The fluorescence properties of 4-(n-butylamino)-9-(n-butyl)-1,8-naphthalimide were investigated in a range of organic solvents including binary solvent mixtures and aqueous solution containing sodium dodecyl sulfate. The environment-dependence of the fluorescence properties indicates a potential for the naphthalimides to be used as fluorescent probes and labels. The heavy atom quenching effect in the fluorescence quantum yields and lifetimes of the 3-bromonaphthalimides have been observed in the selected organic solvents. The fluorescence properties of some naphthalimides have been studied in ethanol and water. Specific solvent effects on the naphthalimide emission properties have been observed. The photophysical behaviour of a series of 4-amino-9-aminoalkyl-1,8-naphthalimides in water were studied as a function of pH. Changes in the absorption and fluorescence properties of the compounds due to the protonation of the 4-amino group were observed and used for calculation of the pKa5 and fluorescence quenching constants of the naphthalimides.
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Han, Hongling. "Investigation of Properties of Polyamido Amine (PAMAM) Dendrimers by Flourescence Spectroscopy." Fogler Library, University of Maine, 2004. http://www.library.umaine.edu/theses/pdf/HanH2004.pdf.
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Nilsson, Ruben. "Optical properties of fluorescence quantum dots for super-resolution bioimaging." Thesis, KTH, Tillämpad fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172345.
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Xu, Hao. "Fluorescence Properties of Quantum Dots and Their Utilization in Bioimaging." Doctoral thesis, KTH, Tillämpad fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191985.
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Quantum dots (QDs), especially colloidal semiconductor QDs, possess properties including high quantum yields, narrow fluorescence spectra, broad absorption and excellent photostability, making them extremely powerful in bioimaging. In this thesis, we studied the fluorescence properties of QDs and attempted multiple ways to boost applications of QDs in bioimaging field. By time-correlated single photon counting (TCSPC) measurement, we quantitatively interpreted the fluorescence mechanism of colloidal semiconductor QDs. To enhance QD fluorescence, we used a porous alumina membrane as a photonic crystal structure to modulate QD fluorescence. We studied the acid dissociation of 3-mercaptopropionic acid (MPA) coated QDs mainly through electrophoretic mobility of 3-MPA coated CdSe QDs and successfully demonstrated the impact of pH change and Ca2+ ions. Blinking phenomena of both CdSe-CdS/ZnS core-shell QDs and 3C-SiC nanocrystals (NCs) were studied. A general model on blinking characteristics relates the on-state distribution to CdSe QD surface conditions. The energy relaxation pathway of fluorescence of 3C-SiC NCs was found independent of surface states. To examine QD effect on ciliated cells, we conducted a 70-day long experiment on the bioelectric and morphological response of human airway epithelial Calu-3 cells with periodic deposition of 3-MPA coated QDs and found the cytotoxicity of QDs was found very low. In a brief summary, our study of QD could benefit in bioimaging and biosensing. Especially, super-resolution fluorescent bioimaging, such as, stochastic optical reconstruction microscopy (STORM) and photo-activated localization microscopy (PALM), may benefit from the modulation of the QD blinking in this study. And fluorescence lifetime imaging (FLIM) microscopy could take advantage of lifetime modulation based on our QD lifetime study.QC 20160905
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Ray, Priyanka. "Calixarenes and Nanoparticles : Synthesis, Properties and Applications." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112131.
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Le travail présenté dans ce manuscrit inclut la synthèse organique des différents types de calixarènes, l'étude de leurs propriétés optiques, des simulations théoriques pour déterminer leurs conformations favorables et leurs utilisations pour stabiliser des nanoparticules. Des nanoparticules d’argent, d’or, de platine et des nanoparticules bimétalliques (Ag-Au) ont été synthétisées en utilisant par réduction radiolytique ainsi que la synthèse la photochimique. Ces nanoparticules sont stabilisées en utilisant des calixarènes et divers polymères. Les nanomatériaux ont été caractérisés par spectroscopie d’absorption UV-Visible et spectroscopie de fluorescence et par des observations en microscopie électronique en transmission. Comme les nanoparticules métalliques sont connues pour leurs applications dans divers domaines, des propriétés antibactériennes de nanoparticules d'argent et des propriétés électrocatalytiques des nanoparticules d'or ont été testéesThe work presented in this manuscript includes the organic synthesis of different types of calixarenes, the study of their optical properties, computational studies for determination of their favourable conformations and their use in the stabilisation of nanoparticles. Silver, gold, platinum and bimetallic (Ag-Au) nanoparticles were synthesised using radiolytic reduction as well as photochemical method. These nanoparticles were stabilised by calixarenes and also other ligands which included several polymers. The nanomaterials were characterised using UV-Visible absorption and fluorescence spectroscopy and transmission electron microscopy (TEM) measurements. As metal nanoparticles are known for their applications in various fields, the antibacterial properties of silver nanoparticles and the electrocatalytic properties of gold nanoparticles were tested
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Finkelmeier, Nils. "Synthesis and Fluorescence Properties of Anthracene Derivatives and their Metal Complexes." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-0023-994A-7.
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Hatton, Ceridwen Sally. "Real-time detection of fronts utilising in vivo phytoplankton fluorescence properties." Thesis, University of Plymouth, 1987. http://hdl.handle.net/10026.1/1709.
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Hudson, Naomi Jane. "Organic matter fluorescence properties of some U.K. fresh and waste waters." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/780/.
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Organic carbon is ubiquitous throughout the aquatic environment. It is an heterogeneous mixture of compounds, some of which are fluorescent, with allochthonous and autochthonous origins. The most common aquatic fluorophores are humic materials (peaks C and A) from degraded plant matter and protein-like material (peaks T1 and T2) of microbial origin. Spectral fingerprints of aquatic organic matter composition may be visualised on an excitation emission matrix (EEM) on which each fluorophore is identifiable as a characteristic peak. Protein-like fluorescence (T1 and T2) is linked to bacterial activity, sewage treatment process efficiency and therefore organic matter bioavailability but its source and fluorescence response is poorly understood. In comparison, peaks C and A are widely studied and have historically been considered to be old, degraded and stable. In this thesis I investigate the character of surface water and effluent fluorescent organic matter using EEMs. I identify the likely origins and bioavailability of common fluorophores and the applicability of fluorescence as a technique for measuring the polluting potential of organic carbon in waters. I also determine changes in sample character and organic carbon concentration, through responses of the common fluorophores, under different environmental conditions and recommend best practice for sample storage.
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Reynolds, Darren Michael. "The spectroscopic properties of wastewater and potential constituents." Thesis, Cranfield University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309710.
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Vasquez, Joan Acay. "Photoluminescent properties of bichromophoric perylenemonoimide and 9-amino-perylenemonoimide." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1446446.
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TAGLIABUE, GIULIA. "Linking vegetation optical properties from multi-source remote sensing to plant traits and ecosystem functional properties." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2019. http://hdl.handle.net/10281/241317.
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Negli ultimi decenni, il telerilevamento è stato utilizzato con successo per monitorare la vegetazione grazie alla sua capacità intrinseca di fornire informazioni quantitative ripetute e spazialmente distribuite circa le sue proprietà. Tuttavia, la ricerca si è concentrata prevalentemente sulla descrizione delle proprietà strutturali e biochimiche della vegetazione piuttosto che sulla comprensione del suo funzionamento.
Negli ultimi decenni, il telerilevamento della fluorescenza della clorofilla indotta dal sole (F) è emerso come strumento innovativo utile allo studio del funzionamento delle piante. F è un debole segnale emesso nelle regioni spettrali del rosso e infrarosso vicino (~650-800 nm) dal cuore dell’apparato fotosintetico per dissipare l’eccesso di energia assorbita. Il suo potenziale risiede nella relazione esistente tra fotochimica e vie dissipative: poiché la fotochimica compete con la dissipazione sotto forma di F e calore, F può essere un indicatore diretto del funzionamento della fotosintesi.
L’obiettivo principale di questo dottorato è stato l’utilizzo di dati ottici (i.e., riflettanza e fluorescenza) per migliorare la comprensione del funzionamento della vegetazione e della sua variabilità spaziale. In particolare, il lavoro si è focalizzato sullo studio del legame tra proprietà ottiche della vegetazione, plant traits (PT) e ecosystem functional properties (EFP) in una foresta di media latitudine. A tale scopo, sono state utilizzate tecniche di telerilevamento innovative per studiare il funzionamento della vegetazione a partire da dati ottici ad altissima risoluzione spettrale acquisiti tramite il sensore aviotrasportato ad immagine HyPlant. Il lavoro si è focalizzato su due obiettivi principali: i) l’analisi della relazione spaziale tra F e EFP per comprendere la variabilità della funzionalità a scala regionale; ii) l’analisi del potenziale di F come indice sintetico della diversità funzionale.
I risultati dimostrano l’efficacia dell’utilizzo di F come proxy della funzionalità della vegetazione, sottolineando allo stesso tempo la complessità del legame tra F, PT e EFP e la necessità di integrare dati differenti per interpretare correttamente il segnale di F. In particolare, i risultati mostrano che: i) F è relazionata alla variabilità spaziale delle EFP, dimostrando che tale relazione tipicamente osservata nel dominio temporale si mantiene in quello spaziale; ii) F è uno strumento più promettente rispetto agli indici tradizionali basati sulla riflettanza per spiegare la diversità funzionale.
Globalmente, i risultati mostrano il ruolo fondamentale dell’eterogeneità spaziale nel controllare l’uptake del carbonio, migliorando così la comprensione della complessa relazione tra F e funzionalità. Futuri studi in questa direzione sono una priorità per migliorare la comprensione del ruolo della vegetazione nel bilancio globale del carbonio.Remote Sensing (RS) data have been successfully exploited in the last decades to monitor vegetation due to their inherent capacity of providing repeated and spatially-distributed quantitative information about vegetation properties. However, most research focused on the description of the structural and biochemical properties of vegetation rather than on the understanding of its functioning. In the last decade, RS of sun-induced chlorophyll fluorescence (F) emerged as a novel and promising tool for assessing plant functional status. F is a weak signal emitted by the core of the photosynthetic machinery in the red and far-red spectral regions (~650-800 nm) as a side product of light absorption. The potential of F relies on the relationship existing between photochemistry and the energy dissipation pathways: since photochemistry competes with F emission and heat dissipation for the absorbed energy, F can be a direct indicator of plant actual functional state. The main aim of this Ph.D. research was to exploit optical data (i.e., reflectance and fluorescence) to advance the understanding of vegetation functioning and of its variability across space. In particular, the work aimed at better understanding the link between vegetation optical properties, plant traits (PTs) and ecosystem functional properties (EFPs) in a case study represented by a mid-latitude forest ecosystem. At this purpose, innovative RS techniques were exploited to infer information about the vegetation functioning from fine and ultra-fine spectral resolution optical measurements acquired with the HyPlant airborne imaging spectrometer. The analyses were focused on two main work streams: i) the investigation of the spatial relationship between F and EFPs to better understand the variability of the ecosystem functioning at regional scale; ii) the analysis of the potential of F as a synthetic descriptor of the ecosystem functional diversity. Results provided evidence of the effectiveness of F as a tool for assessing vegetation functioning, but also pointed out the complexity of the link existing between F, PTs and EFPs and the need to integrate different RS derived products to obtain an unambiguous interpretation of the F signal. In particular, results showed that: i) F can be related to the spatial variability of the EFPs, thus demonstrating that this link usually observed in the temporal domain holds in the spatial domain; ii) F is a more powerful tool compared to traditional reflectance-based indices for explaining the functional diversity. Overall, these results improved the understanding of the complex relationship between F and vegetation functioning by adding new insights into the critical role of the spatial heterogeneity in controlling the carbon uptake. Further research in this direction constitutes a high priority for advancing the understanding of the imprint of plants on the global carbon balance.
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Miasojedovas, Arūnas. "Control of fluorescence properties of organic optoelectronic materials by molecular aggregate formation." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130930_092153-02661.
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Currently, organic electronics is one of the most expanding technology of semiconductor devices. This direction is rapidly developing due to the constant synthesis of new organic compounds and sophisticated advances in device engineering. Currently, organic materials are used in organic light-emitting diodes (OLEDs), organic thin-film transistors, solar cells and sensors. Low-cost manufacturing techniques such as wet casting or inkjet printing enable organic materials use in large-area and flexible electronic devices. Modern organic electronic materials are multifunctional – this enables not only to improve the material properties, but also to simplify the device architecture. However, the complexity of the molecular structure brings new problems associated with complex phenomena of the new multifunctional molecules -such as the formation of aggregates, intramolecular charge transfer, intramolecular torsion and others. Therefore, the control of the features of new multifunctional molecules is the main problem of organic electronics today. This work focuses on the control of photophysical characteristics of multifunctional organic emitters. Here we study aggregation induced emission and quenching of multifunctional molecular emitters and the possibilities to control these phenomena by optimizing functional properties of the film such as film forming properties, charge transfer, the emission efficiency, amplified spontaneous emission threshold and others.Organinė elektronika pastaruoju metu yra viena sparčiausiai besiplėtojančių puslaidininkių prietaisų krypčių. Ši kryptis labai sparčiai vystoma dėl nuolat kuriamų naujų organinių junginių ir tobulėjančių inžinerijos galimybių. Šiuo metu organinės medžiagos naudojamos organiniuose šviestukuose (OLED), plonasluoksniuose tranzistoriuose, saulės celėse, jutikliuose ir kt. Organinės medžiagos įgalina gaminti didelio ploto bei lanksčius elektronikos prietaisus, gamybai pasitelkiant pigias gaminimo technologijas. Modernios organinės elektronikos medžiagos yra daugiafunkcinės – tai leidžia ne tik pagerinti medžiagos savybes, bet ir supaprastinti technologiją, kur viename sluoksnyje daugiafunkcinė molekulė atlieka keletą funkcijų. Tačiau molekulinės struktūros sudėtingėjimas iškelia naujas problemas susijusias su naujais sudėtingais reiškiniais daugiafunkciniame molekuliniame darinyje, tokiais kaip agregatų formavimas, vidujemolekulinė krūvio pernaša, vidujemolekulinė sąsūka ir kt. Todėl naujų daugiafunkcinių molekulinių darinių savybių optimizavimas yra aktuali nūdienos organinės elektronikos problema. Šiame darbe didžiausias dėmesys skiriamas daugiafunkcinių organinių spinduolių fotofizikinių savybių valdymui. Čia nagrinėjami daugiafunkcinių molekulinių spinduolių agregacijos nulemti reiškiniai ir jų valdymo galimybės, optimizuojant sluoksnio funkcines savybes tokias kaip plėvėdaros savybės, krūvio pernaša, emisijos našumas, sustiprintos savaiminės spinduliuotės slenkstis ir kt.
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Londinová, Monika. "Fluorescence ve výzkumu hydrofilních oblastí asociativních koloidů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216403.
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The properties of the hyaluronan were investigated by using different fluorescence probes, because hyaluronan is a hopeful carrier of an active matter in medicine and cosmetics. Selected fluorescence probes were: cationic acridine orange, Nile Blue A, methylene blue, amphiphilic 4-Di-2-ASP and anionic fluorescein. Except from fluorescence and absorption spectra of the probes were observed electrostatic and hydrophobic interactions as well. The probes in solvents with different polarity (MeOH, EtOH, DMSO) showed the bathochromic shift in the emission maximum and quenching of the fluorescence with the increasing polarity of the solvents. The influence of the ionic strength on fluorescence properties of the probe acridine orange and 4-Di-2-ASP was investigated in aqueous solutions of chlorides. The formation of acridine orange dimer is inhibited with increasing ionic strength. CaCl2 increased the ionic strength the most, then prevented repulsion of carboxylate groups, so it means the expansion of hyaluronan cluster into the solution. However, the emission of the probe 4-Di-2-ASP was quenched with the addition of CaCl2 the most. The first additions of COO– groups cause the formation of dimers of AO shown as decreasing in extinction coefficient and fluorescence intensity. Next addition of the hyaluronan caused a depolymerization of formed dimers and the increase of the emission intensity. The repolymerization caused the decrease and then again the increase. In case of 4-Di-2-ASP was the pattern of the fluorescence (the intensity and the position of the emission) firstly the same, but at the concentration of 1 g dm-3 the emission intensity increased. The probes MB and F were used for spectroscopic studies of the interaction between methylene blue-fluorescein complex and anionic and cationic surfactants. The absorbance of separate MB and F changed only with the addition of surfactants with the opposite electric charge. Absorbance of the mixture MB-F changed with the addition of the CTAC surfactant, while the addition of SDS into the mixture caused only the change of MB absorption spectra.
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Yao, Dandan. "Synthesis of new conjugated meso porphyrin dendrimers and oligomers and study of their optical properties." Thesis, Rennes, INSA, 2015. http://www.theses.fr/2015ISAR0008/document.
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Au cours de cette thèse, nous avons synthétisé et caractérisé de nouveaux composés en utilisant le macrocycle porphyrine en tant que brique moléculaire. L’objectif, après la synthèse, était d’étudier les propriétés photophysiques de ces nouvelles molécules. Plus précisément, nous avons considérés trois groupes de dendrimères fluorènyles-porphyrines et deux oligomères avec des structures conjuguées. Les corrélations structures et propriétés optiques ont été discutées en détail, ainsi que le transfert d’énergie du dendron conjugué donneur. Dans le premier chapitre, nous avons décrit la chimie des porphyrines en considérant surtout trois aspects: (i) structure, (ii) propriétés optiques et (iii) méthode synthétique. Nous avons également reporté les porphyrines préalablement étudiées dans notre groupe de recherche et proposé de nouveaux modèles lors de cette thèse. Dans le deuxième chapitre, nous avons étudié l’influence de la position de substitution du phényle sur le coeur central qui est la porphyrine TPP. Deux groupes de nouveaux dendrimères ont été synthétisés avec différentes positions de substitution du phényle de la TPP: série parasubstituée TPP1, TPP2 et TPP3, et série méta-substituée TPP4, TPP5 et TPP6. Ces dendrimères ont tous des dendrons conjugués avec des ponts phényl-alcynes et des groupements fluorènyles terminaux. Dans le troisième chapitre, pour étudier l’influence des antennes périphériques, une série de dendrimères de porphyrine à base de TFP avec différentes positions de fluorènyles dans les dendrons conjugués (fluorényle central, fluorényle pontant et fluorényle terminal): TFP1, TFP2 et TFP3 a été synthétisée. Le fluorényle central influence principalement l’émission et le rendement quantique, alors que le fluorényle ponté et le fluorényle terminal ont un plutôt un effet sur l’absorption et l’émission du dendron en raison du transfert d’énergie prenant effet. Pour le plus gros dendrimère TFP3, lors de l’excitation du dendron, une émission résiduelle lors du processus de transfert est observée due à une trop grande distance entre ce chromophore et le coeur de la porphyrine. Dans le quatrième chapitre, afin d’étudier l’influence des connexions dans le dendron, deux nouveaux dendrimères de porphyrine incorporant des ponts vinyles et alcynyles, TPP-D et TFP-D, ont été synthétisés et comparés aux analogues avec des ponts alcynes TPP-T et TFP-T. Ces ponts avec des doubles liaisons influencent dans une certaine mesure les propriétés optiques des dendrimères de porphyrine en fonction des positions occupées. Dans le dernier chapitre, deux oligomères (un dimère linéaire et en un trimère en étoile), ont été synthétisés à partir du même monomère de porphyrine avec TFP comme groupement terminauxDuring this thesis, we have worked on the synthesis and characterization of new compounds using the porphyrin macrocycle as a starting material. The aim, after synthesis, was to study the photophysical properties of these new molecules. More precisely, we have synthesized and characterized three groups of fluorenyl-porphyrin dendrimers and two oligomers in conjugated structures. Their correlation on optical property-structure have been discussed in detail, as well as the energy transfer processes from the conjugated dendron donor to porphyrin acceptor. In the first chapter, we introduce the general background of the porphyrin chemistry based on three aspects: (i) structure, (ii) optical properties and (iii) synthetic methods. We further review prior porphyrin studies done in our group and propose new molecular designs based on these results. In the second chapter, we study the influence of substitution position and nature of the antennae on the central core. Two groups of new TPP-cored porphyrin dendrimers were synthesized according to different substituted positions on the peripheral phenyl rings: para-substituted series TPP1, TPP2 and TPP3, and meta-substituted ones TPP4, TPP5 and TPP6. All have conjugated dendrons with bridged phenyl-alkynyl and are terminated by fluorenyl groups. In the third chapter, we study the influence of positions of light absorbers. To this aim, a series of TFP-cored porphyrin dendrimers presenting fluorenyls in conjugated dendrons on different positions is reported (core fluorenyl, bridging fluorenyl and terminal fluorenyl): TFP1, TFP2 and TFP3. The core fluorenyl mainly influences emission peaks and quantum yield, while the bridging fluorenyl and terminal fluorenyl have a large effect on the dendron absorption and on the energy transfer efficiency. Thus, for the largest dendrimer TFP3, dendron emission is not totally quenched by long distance energy transfer process when exciting the peripheral dendrons. In the fourth chapter, we study the influence of linkages in the Dendron. Thus, two new porphyrin dendrimers with bridged vinyl, TPP-D and TFP-D, were synthesized and compared to analogues with alkynyl bridged TPP-T and TFP-T. Vinyl and alkynyl bridges are shown to influence the optical properties of the porphyrin dendrimers to a certain extent depending on the substituted positions. Finally, in the last chapter, two oligomers with n-butyl substituted TFP as terminal group, a linear dimer and a star – shaped trimer, were synthesized from the same porphyrin monomer
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Jusic, Dragana. "Properties of LEDs for the Calibration of PMTs for the Daya Bay Project." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/36400.
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The flavor oscillations of neutrinos due to the mixing of mass eigenstates have been thoroughly studied in several experiments. One missing piece of the puzzle is the mixing angle θ13, which is being searched for by the Daya Bay experiment. Currently, the experiment is still in construction mode. Part of the experiment involves building effective detectors for atmospheric muons, resulting in accurate detection of antineutrinos from the source. To ensure accurate detection, we must effectively calibrate the PMTs with the use of carefully chosen and calibrated LEDs. This thesis details the study of several LEDs measured in an attempt to determine the properties of the most likely source for our calibration efforts. I measured the spectra of the LEDs meant for use in calibration, along with several others for the purpose of comparison of spectrum width and to find the evidence of fluorescence in the LEDs.Master of Science
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Bellacanzone, Christian. "Tuning of the poly(p-phenylenevinylene) derivativesemission properties by phase change materials andsonochemistry." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/664005.
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Los polímeros conjugado (CP) son un material muy interesante con propiedades optoelectrónicas peculiares que hacen de estos polímeros óptimos candidatos por distintas aplicaciones cuáles OLEDs y celdas organicas fotovoltaicas y también por bioimagen y liberación de fármacos. En los últimos años creciente atención se ha dirigido hacía la modulación de las prioridades ópticas de los CP para poderlos emplear en distintos ámbitos. El objetivo de este trabajo es de lograr un ajuste fino de la emisión de los derivados de polifenileno vinileno (PPV) . Dos estrategias principales se han adoptados. I) Nanoparticulas de oligomeros de PPV con distintas longitudes de conjugación se han producido mediante síntesis sonoquímica. La irradiación con ultrasonidos ha sido aplicada a una solución heterogénea de polímero PPV para inducir la activación de especies radicales que rompen los enlaces doble del polímero cortándolo y generando oligomeros de PPV. La copresencia de un tensioactivo dirige la simultánea nanostructuración de los oligomeros generando nanoparticulas soluble en agua que presentan un progresivo cambio hipsocrómico de las bandas espectrales en absorción y emisión comparado con el polímero inicial. Tal nanoparticulas pueden ser utilizadas en OLEDs y bioimagen. II) los oligomeros y el polímero de PPV fueron mezclados con materiales a cambio de fase de distinto punto de fusión. Cuando tal sistema mixto es calentado, se induce la transición de solido a liquido en el PCM provocando un cambio de fluorescencia hacía el azul. Una vez que el sistema se enfríe y solidifica la emisión inicial es recuperada. Semejante sistema se puede utilizar por la fabricación de sensores de temperatura florecientes y multicolores. También podrías destinar a la realización de diodos orgánico de luz blanca termoregulados aprovechando de la emisión roja, verde y blue de los oligomeros obtenidos en este trabajoConjugated polymers (CP) are interesting materials with peculiar optoelectronic properties which make this class of polymers good candidate for several applications such as OLEDs, organic photovoltaics, but also for bioimaging and drug delivery. In the last decades, increasing attention has been directed to the tuning of the emission properties of CP to fully exploited their application in several fields. The aim of this thesis work is to achieve a fine emission tuning of a polyphenylene vinylene (PPV) derivatives. Two main strategies have been adopted. I) Nanoparticles of PPV oligomers with different conjugation length was obtained through sonochemical synthesis. Ultrasound irradiation of PPV polymer heterogenous solution was employed to induce the activation of radical species which cut the polymer chain forming PPV oligomers. The copresence of surfactant leads to a simultaneous nanostructuration of such oligomers producing water-soluble nanoparticles which exhibited a progressive hypsochromic shift of absorption/emission compared to the parental polymer. These nanoparticles that emitted in a wide range of the visible electromagnetic spectrum are promising materials for application such as polymers LEDs and bioimaging. II) The PPV polymers and oligomers were mixed with phase change materials with different melting point. Upon heating, solid-to-liquid phase transition is induced in the PCM/PPV system and its fluorescence is blue shifted. Once the system is cooled down the initial emission is recovered. Such system could be applied as multicolour emitting temperature sensor, or for thermoregulated white organic light emitting diode, thanks to the red, green and blue emission of the PPV derivatives obtained in this work.
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Sui, Ning. "Synthesis, characterization and optical properties of hybrid nanoparticles working with plasmon-fluorescence coupling." Phd thesis, Ecole Centrale de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00781927.
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L'exaltation de fluorescence par un métal est de plus en plus utilisée pour augmenter la sensibilité de détection dans les systèmes utilisant la fluorescence. Au cours de ce travail de thèse, nous avons étudié ce phénomène dans des nanoparticules hybrides Métal@SiO2 possédant des émetteurs de fluorescence immobilisés sur la silice. Dans un premier temps, nous avons élaboré les nanoparticules cœur-coquille Métal@SiO2 (Métal = Au ou Ag) en utilisant différentes méthodes et en les comparant pour choisir la plus adaptée selon le diamètre du cœur métallique. Dans un deuxième temps, nous avons étudié les propriétés de fluorescence exaltée des nanoparticules hybrides. Deux types d'émetteurs de fluorescence ont été sélectionnés : des nanoparticules semi-conductrices (SiC) et des fluorophores organiques (cyanine 3 et fluorescéine). Après fonctionnalisation de la silice, les émetteurs de fluorescence ont été greffés à la surface des nanoparticules Métal@SiO2. L'exaltation de leur fluorescence a été analysée en fonction de leur densité surfacique, de leur distance par rapport au cœur métallique (fixée par l'épaisseur de silice), du diamètre du cœur métallique et de la longueur d'onde d'excitation. Le facteur d'exaltation le plus important (de l'ordre de 103) a été obtenu avec une faible épaisseur de silice (10 nm) pour les nanoparticules de SiC dont le rendement quantique intrinsèque est très faible (inférieur à 1%). Enfin, la surface de nanoparticules hybrides a été fonctionnalisée avec des nanoparticules d'oxyde de fer de manière à obtenir une combinaison de propriétés optiques (fluorescentes et plasmoniques) et magnétiques à l'intérieur d'une même nanoparticule hybride.
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Daswani, Varsha. "Fluorescence and aggregation properties of the anti-cancer drug, CA4P, in archaeal liposomes." Diss., Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/334013.
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Biomedical SciencesPh.D.
Combretastatin A4 phosphate (CA4P) is a potent vascular disrupting agent utilized in the treatment of cancer. The observed rapid vascular shutdown post administration as well as its potency at 1/10th of the established maximum tolerated dose (MTD) have made it one of the most prevalent tubulin binding agents. CA4P is currently involved in 19 clinical trials. Unfortunately, as is the case with most forms of chemotherapy, the off target effects associated with its use can be prohibitive for a large percentage of cancer patients. The advantages associated with the liposomal encapsulation of chemotherapeutic agents have been established for over 20 years and are shown to decrease off target effects whilst increasing stability, bioavailability, and circulation time. Liposomes comprised of conventional phospholipids, such as 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), are usually stabilized by the incorporation of cholesterol. However, the addition of cholesterol to liposomal formulations is concerning due to the capability of cholesterol to form oxysterol molecules and exacerbate other preexisting conditions such as hypertension or cardiovascular disease. With this study we aim to enhance the usage of CA4P through liposomal encapsulation in order to reduce some of the associated off target effects and increase bioavailability and overall efficacy. We also aimed to enhance the stability of our lipid vesicles through the incorporation of bipolar tetraether lipids isolated from the thermoacidophilic archaea S. acidocaldarius. The polar lipid fraction E (PLFE) lipids studied here have previously been shown to generate highly stable lipid vesicles. The liposomal formulation studied here included the encapsulation of the anti-cancer drug CA4P in PLFE liposomes. With this work we characterized our liposomes to optimize their drug loading, membrane stability, size, colloidal stability, and membrane surface charge. We also identified a photochemical isomerization reaction occurring in our CA4P samples and then proceeded to characterize the fluorescence and aggregation behavior of our CA4P isoforms. From our studies of CA4P in solution we observed a red shift in the excitation spectra of CA4P with increasing concentrations. This bathochromic shift is characteristic with the formation of j-aggregates. The CA4P concentrations with the most dramatic red shift corresponded exactly with the drug concentrations associated with self-quenching behavior. From these studies we determined the effects of increased CA4P concentration on fluorescence intensity, drug aggregation and how these phenomena can be utilized and exploited to maximize liposomal drug loading and decrease rate constants of drug leakage and cytotoxicity. The end goal of liposomal chemotherapeutic formulations is a stable, controlled release of as much encapsulated drug as possible. With the thorough understanding of our membrane system, drug fluorescence and CA4P aggregation behavior; we can maximize our encapsulated drug loading as well as create a stable liposomal formulation with a predictable CA4P release.
Temple University--Theses
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Upamali, Karasinghe A. Nadeeka. "Carbazole-Based, Self-Assembled, Π-Conjugated Systems As Fluorescent Micro And Nanomaterials - Synthesis, Photophysical Properties, Emission Enhancement And Chemical Sensing." Bowling Green State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1323099511.
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Bonneau, Mickaële. "Synthesis and Luminescence Properties of New Platinum and Iridium Complexes." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S114/document.
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Les travaux de cette thèse portent sur la synthèse et les études en photoluminescence de nouveaux complexes de métaux de transitions (Ir(III), Pt(II), Pd(II)). Le principal objectif est d’obtenir de nouveaux matériaux phosphorescents pour des applications telles que les diodes organiques électroluminescentes (OLEDs) ou la bio-imagerie. L’incorporation de chromophores tels que le pyrene et le naphtalimide au complexe fac-Ir(thpy)3 sera tout d’abord présenté. La synthèse par activation C–H de ces nouveaux complexes sera également étudié. De nouveaux complexes organométalliques ultra-rigides seront ensuite développés. La synthèse ainsi que les analyses en photoluminescence de complexes tetradentate de platine et de palladium seront ensuite décrits. Enfin, une analyse de nouveaux complexes d’iridium comportant des ligands benzimidazoles (iso)-quinoline et bis-benzimidazole sensibles aux variations de pH sera faiteThe work of this thesis is focused on the synthesis and the photoluminescence studies of new 3 raw transition metal complexes (Ir(III), Pt(II), Pd(II)) . The main objective is to obtain new phosphorescent materials for applications such as organic light emitting diodes (OLEDs) and bio- imaging. The incorporation of chromophores such as pyrene and naphthalimide into fac-Ir-(thpy)3 complex will first be presented. The synthesis, by C–H activation, of the new complex will also be studied. New ultra-rigid organometallic complexes will then be developed. The synthesis and the photoluminescence analysis of these tetradentate platinum and palladium complexes will be described. Finally, a study of new iridium complexes incorporating benzimidazoles (iso)-quinoline and bis-benzimidazole ligands sensitive to pH variations will be made
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Romano, Natalie C. "Photophysical Properties of Amphiphilic Naphthalene Diimide Nanoassemblies and Cadmium Sulfide Nanoparticles and Poly(phenylene-ethynylene) Nanocomposites." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1399035654.
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Morris, Ian Patrick. "Synthesis and properties of novel 4,5-diaminonaphthalimides." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297381.
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Fernando, Nilmi T. "Novel Near-Infrared Cyanine Dyes for Fluorescence Imaging in Biological Systems." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/chemistry_diss/57.
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Heptamethine cyanine dyes are attractive compounds for imaging purposes in biomedical applications because of their chemical and photophysical properties exhibited in the near-infrared region. A series of meso amino-substituted heptamethine cyanine dyes with indolenine, benz[e]indolenine and benz[c,d]indolenine heterocyclic moieties were synthesized and their spectral properties including fluorescence quntum yield were investigated in ethanol and ethanol/water mixture. Upon substitution with amines, the absorption maxima of the dyes shifted to the lower wavelength region (~600 nm), showed larger Stokes shifts and stronger fluorescence which can be attributed to an excited state intramolecular charge transfer (ICT). High quantum yields were observed for primary amine derivatives and lower quantum yields were observed for secondary amine derivatives. Fluorescence quantum yields are greater for dyes with 3H-indolenine terminal moieties than for dyes with benz[e]indolenine end groups. Benz[c,d]indolenine based heptamethine cyanine dyes exhibited the lowest quantum yield due to aggregation in solution. In general, the benz[e]indolenine hepatemethine cyanines showed high Stokes shifts compared to indolenine dyes. For the meso-chloro dyes, the absorption maxima for the dyes shifted bathochromically in the order of indolenine, benz[e]indolenine and benz[c,d]indolenine.
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Herbert, Sébastien. "Dynamics and physical properties of the chromatin after DNA damage." Paris 7, 2014. http://www.theses.fr/2014PA077216.
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Au cours de la dernière décennie, l'organisation et la mobilité de la chromatine se sont imposées comme des facteurs épigénétiques majeurs. Elles affectent et sont affectées par plusieurs mécanismes biologiques fondamentaux, telles l'expression des gènes et les cassures double brin (DSB). Pour ce projet, nous avons choisi l'eucaryote unicellulaire Saccharomyces cerevisiae comme organisme modèle en raison de sa structure nucléaire relativement simple, son génie génétique simplifié et sa grande base bibliographique. De plus, les petites dimensions de la levure bourgeonnante facilitent une acquisition rapide d'un large volume de données et une analyse statistique robuste. Enfin, une partie des mécanismes biologiques fondamentaux, telle la réparation de l'ADN étudiée ici, est hautement conservée chez les eucaryotes. En comparant nos données expérimentales d'organisation nucléaire à des données simulées, produites en parallèle de ce travail, basées sur la physique des polymères, nous avons démontré que l'auto-organisation des chromosomes est suffisante pour reproduire l'organisation globale observée expérimentalement. Nous avons ensuite décrit la mobilité d'un subtélomère à l'aide d'un système dédié de microscopie par fluorescence et de nouvelles analyses numériques. Cette mobilité présente 2 régimes : sous diffusif à court terme (typique d'un polymère) et confiné à long terme (en partie dû à l'encombrement du noyau et à l'ancrage des chromosomes). Enfin, nous avons étudié l'origine de l'augmentation de la mobilité des chromosomes après l'induction de DSB. Nous avons également démontré l'absence de modification de la rigidité et de la compaction de la chromatine après cassureDuring the last decade, organization and mobility of the chromatin have emerged as major epigenetic factors. They affect and are affected by a number of fundamental biological mechanisms such as gene expression and double¬strand breaks (DSB). For this project, we chose the eukaryotic unicellular Saccharomyces cerevisiae as a model organism because of its relatively simple nuclear structure, simplified genetic engineering and large bibliographie database. Moreover, the small dimensions of the budding yeast facilitate a rapid acquisition of large datasets and a robust statistical analysis. Finally, a part of fundamental biological mechanisms, such as DNA repair investigated in this work, are highly conserved in eukaryotes. By comparing our experimental data of nuclear organization to simulated data, produced in parallel of this work, based on polymer physics, we have demonstrated that chromosomes self-organization is sufficient to reproduce the experimentally observed global organization. We then described die mobility of a subtelomere using a dedicated fluorescence microscopy system and new numerical analyzes. This mobility can be represented by 2 diffusion models at different lime intervals: short-tenu subdiffusion (typical in die case of a polymer) and long-term confinment (partly due to die crowded environment and chromosome anchoring). Finally, we studied the origin of the increased mobility of chromosomes after induction of DSB. We have also demonstrated the absence of modification of the chromatin's stiffness and compaction after DSB
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Altamimi, Rashid M. "Synthesis and Photophysical Properties of Porphyrin-Containing Supramolecular Systems." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1291171941.
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Comesaña-Hermo, Miguel. "Synthesis of cobalt-based nanohybrids and study of their magnetic and optical properties : carbon coating and functionalization with luminescent dyes." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1229/.
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Les nanoparticules (NPs) magnétiques sont envisagées pour plusieurs applications très différentes comme le stockage magnétique d'information, la catalyse ou la médecine. Certaines propriétés indispensables pour ces applications sont liées à l'état de surface des NPs et à leur anisotropie. Pour répondre à cette demande, nous avons fonctionnalisé la surface de particules de Co de façon à les stabiliser vis-à-vis de l'oxydation et proposé une synthèse de NPs de morphologie optimisée. Plus précisément, des nanofilaments de Co ont été recuits post-synthèse selon un procédé préservant leur morphologie. Nous avons montré que la couche de carbone formée protège efficacement les NPs de l'oxydation. D'autre part, nous avons synthétisé des NPs de Co en utilisant un fluorophore organique (Rhodamine B) comme unique agent stabilisant. Ce système nous a permis d'étudier l'effet du cœur magnétique sur les propriétés optiques du fluorophore et, au même temps, d'observer comment l'excitation de la molécule liée à la surface peut induire une modulation de l'aimantation de la particule. Le même fluorophore a été utilisé pour la synthèse des NPs, conduisant à la formation de nanodisques. Ces particules sont monodomaines, bloquées à la température ambiante, paramètres fondamentaux pour leur possible implémentation dans le domaine du stockage magnétiqueCobalt nanoparticles (NPs) are important materials for applications in very different fields like magnetic storage technology, catalysis or medicine. These applications require different properties that are related with the surface state of the original particles. In this thesis we have functionalized the surface of isotropic and anisotropic Co NPs in order to fulfill this demand. Pre-synthesized Co nanowires have been submitted to a thermal treatment that permits the formation of carbon coated anisotropic objects, overcoming therefore one of the main limitations of this kind of materials: their instability towards oxidation. In other order of things, we have synthesized small Co NPs with a fluorophore (Rhodamine B) as unique stabilizer. Such system presents a very interesting opportunity to study the effect of the magnetic core over the optical properties of the dye and, at the same time, to observe how an excited organic molecule directly attached to the Co surface can have an effect over the magnetic properties of the particle. The same dye has been used under other synthetic conditions to promote the anisotropic growth of Co NPs, leading to the formation of monodisperse Co nanodisks. These particles present blocked behavior at room temperature, being therefore interesting materials for magnetic data storage devices or permanent magnets
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Nieves, Calatrava Ingrid. "Polyene sphingolipids with latent fluorescence: new tools to study the biophysical properties of cellular membranes." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/347964.
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One of the ultimate goals in biomedicine is to understand the relationship between structure, function, and dynamics of biomolecules in living cells. The biophysical tools designed to gain more insight into metabolism, trafficking and interaction of the sphingolipids (SLs), require the use of high molar concentrations of fluorescence lipid analogues, labelled with bulky chromophores, such BODIPY or NBD, resulting in altered biophysical properties of the cell membrane.
Recently, lipids tagged with conjugated linear polyene moieties, which are strongly absorbing chromophores that may attain modest but useful fluorescence yields, have been reported to behave in vivo like their endogenous counterparts. Nevertheless, when these labelled lipids are part of the N-acyl or the O-acyl chains of the SLs, the fluorophore can be released by hydrolysis of the amide or the ester bonds, and the resulting sphingoid base is no longer traceable.
Taking into account the above considerations, the main objective of this thesis is to synthesize novel intrinsically-fluorescent sphingosine (Sph) and ceramide (Cer) probes, labelled with five conjugated double bonds in the sphingoid base backbond, in order to analyse membrane microdomains that are temporarily enriched in certain lipids. Additionally, the fluorescence of these probes can be modulated with total spatiotemporal control by the presence of a suitable radical quencher that can be removed by the action of a specific enzyme.
Initially, as a proof of concept, three probes derived from γ-aminobutyric acid (GABA), based on a conjugated pentaene system with a radical scavenger (n-DOXYL free radical group) at different positions, were synthesised. These probes are structural analogues of palmitoyl-Cer lacking the hydroxyl group at C1 of the sphingoid chain. In addition, the secondary hydroxyl group at C3 has been replaced with an ester group. Despite the overall effect is a lower polarity of the headgroup, GABA-pentaene probes were still useful tools to evaluate the biophysical properties of these dual fluorophore-quencher systems in model membranes. With the GABA-pentaene probes in hand, different biophysical studies were developed in lipid vesicles. Fluorescence studies, differential scanning calorimetry and electron paramagnetic resonance measurements exhibited the ability of these probes to detect membrane lipids in gel phase, being relevant in view of the novel evidences pointing at the existence of gel microdomains in cell membranes. In addition, these Cer analogues may be particularly useful probes for the observation of highly-ordered bilayers by confocal microscopy, since its emission was higher in gel than in fluid domains, and in liquid-ordered than in liquid-disordered areas.
Finally, different synthetic protocols for the construction of conformationally constrained pentaene-Sph and -Cer analogues were designed. The combination of Horner-Wadsworth-Emmons (HWE) and Wittig olefinations gave access to triene and pentane alkyne intermediates. In turn, these alkynes were found to be versatile synthons for the preparation of SLs analogues. By means of nucleophilic alkynylations, polyenyne-Sph analogues were obtained, whereas a hydrozirconation approach allowed the synthesis of the first pentaene palmitoyl-Cer analogue. Additionally, in light of the apparent instability of the conjugated pentaene system under acidic conditions, an alternative unreported serinal derivative building block was synthesised, which enabled a selective deprotection under mild basic conditions.
Overall, synthetic approaches to polyene sphingosine analogues have been achieved. Remarkably, the pentaene moiety has been introduced in the sphingoid base backbond for the first time, providing new tools to directly observe their distribution in lipid bilayers. In addition, biophysical studies revealed the suitability of polyene moieties for fluorescence detection, by means of the simplified models GABA-pentaene probes.Actualmente, uno de los retos de la biomedicina es profundizar más en el metabolismo, señalización e interacciones de los esfingolípidos (SLs), mediante empleo de técnicas biofísicas que no alteren las propiedades de las membranas celulares. El estudio y la visualización de los SLs, generalmente, va asociado al uso de concentraciones molares muy elevadas de sondas marcadas con grupos fluorescentes, cuyos cromóforos presentan estructuras rígidas, de considerable tamaño y volumen (NBD, BODIPY), generando un escenario artificial que dista de las condiciones fisiológicas. Con objeto de reducir el impacto que produce el volumen de los grupos cromóforos en la estructura y empaquetamiento de los lípidos de membrana, se han utilizado sistemas de dobles enlaces conjugados, fluorescentes, los cuales se comportan in vivo de forma similar a sus análogos naturales. Sin embargo, hasta el momento, no se ha diseñado ninguna sonda que contenga el sistema pentaénico incorporado en la estructura de la base esfingoide, el cual permitiría observar la distribución de especies tipo esfingosina (Sph), por visualización directa. Con objeto de analizar los microdominios de membrana que son temporalmente enriquecidos en ciertos lípidos, en la presente tesis doctoral se han diseñado diversos protocolos sintéticos para la obtención de sondas análogas a la Sph y a la ceramida (Cer). Las nuevas sondas obtenidas, pentaenino-Sph y palmitoil pentaeno-Cer, han sido marcadas, por primera vez, en la base esfingoide con una estructura de cinco dobles enlaces conjugados, confiriendo un sistema intrínsecamente fluorescente. Además, el diseño de los pentaeno-SLs permite la introducción en la cadena N-acilo de un agente radical atenuador interno (n-DOXYL), el cual latentizaría la fluorescencia con total control espaciotemporal. Por acción de una enzima específica, se liberaría el atenuador, recuperando la fluorescencia del sistema pentaénico, lo que permitiría la visualización directa de los SLs a concentraciones más cercanas a las fisiológicas. Asimismo, como prueba de concepto, se han sintetizado tres sondas derivadas del ácido γ- aminobutírico (GABA), como modelos simplificados de la palmitoil-Cer natural, los cuales contienen un sistema pentaénico con un atenuador radicalario en la misma molécula. Los ensayos biofísicos llevados a cabo en membranas modelo con estas sondas alternativas, nos han proporcionado información interesante de las propiedades biofísicas que presenta el sistema dual pentaeno-atenuador radicalario en un entorno lipídico.
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Tománková, Lenka [Verfasser], and J. [Akademischer Betreuer] Blümer. "Optical Properties and Calibration of the Pierre Auger Fluorescence Detector / Lenka Tománková ; Betreuer: J. Blümer." Karlsruhe : KIT-Bibliothek, 2016. http://d-nb.info/1120498147/34.
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Sahoo, Harekrushna [Verfasser]. "Investigation of structural, conformational, and dynamic properties of polypeptides by fluorescence-based techniques / Harekrushna Sahoo." Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2008. http://d-nb.info/1034893602/34.
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Herron, Lissa. "Determining Which Tryptophan Residues Give Rise to Fluorescence Properties in the Metallo-Beta-Lactamase L1." Miami University Honors Theses / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1110916836.
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Antoku, Yasuko. "Fluorescent Polycytosine-Encapsulated Silver Nanoclusters." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14568.
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Small silver nanoclusters are synthesized using polycytosines as matrices. Different size silver nanoclusters ranging from Ag1 to Ag7 exhibit bright emission maxima at blue (480nm), green (525nm), red (650nm), and IR (720nm) wavelengths with varying the excitation wavelengths. With electrophoresis, correlation of emission with mass spectra, the Ag cluster sizes are identified with blue emitters as Ag5, green emitters as Ag4, red emitters as Ag3, and IR emitters as Ag2. Ag4 and Ag5 appear to be partially oxidized while Ag2 and Ag3 are likely fully reduced.
Silver cluster stability and their dynamics are observed from silver clusters encapsulated by polycytosine (Cm:Agn). From length study of polycytosine, the longer the polycytosine is, the more stable the larger clusters such as Ag5 are. In time-dependent optical measurements, isosbestic points are observed from Cm:Agn by converting red and IR species into blue and green species, while in the case of temperature-dependent optical properties, with increasing temperature, the blue (oxidized Ag5) and green (oxidized Ag4) emitters convert into the red (Ag3) and IR (Ag2) emitters. NaCl-dependent optical measurements support the assignments of oxidized and fully reduced silver emitters. Circular dichroism (CD) is used to investigate conformational changes in Cm and Cm:Agn with varying conditions (time, temperature and NaCl) and the studies indicate that no conformational changes in Cm:Agn are observed from the time and temperature, while the conformational changes in Cm:Agn are observed from the NaCl studies. From pH-dependent emission study of Cm:Agn, the silver nanocluster dynamics slow down at high pH.
Using confocal microscopy technique, single molecules on IR species, C12:Ag2 are investigated and demonstrate that C12:Ag2 is brighter and more photostable than Cy5 which is known to be one of the best IR dyes. With low excitation power, molecules can be monitored for hours, giving bright blinking free, stable fluorescence. The photophysics of this new dye make it a promising candidate for single molecule studies in biological applications.
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Thomson, Cameron Ian. "Probing the Nature of Cellulosic Fibre Interfaces with Fluorescence Resonance Energy Transfer." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16277.
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The material properties of fibre networks and fibre reinforced composites are strongly influenced by fibre-fibre interactions. Stress transfer between load bearing elements in such materials is often dictated by the nature of the fibre-fibre interface. Inter-fibre bonding is solely responsible for internal cohesion in paper, because all stresses transferred between fibres operate through fibre-fibre bonds. . The future development of cellulosic fibre materials will require an improved understanding of the fibre-fibre interface. Fluorescence resonance energy transfer (FRET) was proposed as a new tool for the study of fibre interfaces.
A protocol for covalent linkage of fluorophores to natural and regenerated cellulosic fibres was developed and the absorptive and emissive properties of these dyes were characterized. The fluorescent response of these dyed fibres in paper sheets was studied using steady-state fluorescence spectroscopy. Fluorescence micrographs of fibre crossings on glass slides were analyzed using the FRETN correction algorithm. Energy transfer from coumarin dyed fibres to fluorescein dyed fibres at the interface was observed. The FRETN surfaces for spruce and viscose rayon fibre crossings were distinctly different. The FRET microscopy method was able to detect statistically significant differences in spruce fibre interface development when fibre fraction and wet pressing were varied. The coalescence of natural cellulosic fibre interfaces during drying was also observed with the technique.
Polysaccharide films were employed as model systems for the natural and regenerated cellulose fibre interfaces. It was found that pressing cellulose films did not result in significantly increased FRETN either due to resistance to deformation or the inability to participate in interdiffusion. Conversely, xylan films demonstrated a drastic increase in the FRETN signal with increased wet pressing. These results support the previously observed differences between regenerated cellulose fibres and natural wood fibres. The results of the FRETN analysis of the polysaccharide film model systems suggest that lower molecular weight amorphous carbohydrates are likely to be significant contributors to fibre interface development.
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Soemo, Angela Renee. "Microenvironment of Monorhamnolipid Biosurfactant Aggregates and Monorhamnolipid Effects on Aqueous Dispersion Properties of Metal Oxide Nanoparticles." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293563.
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The purpose of this dissertation was two-fold: 1) explore the micelle structure and microenvironment of monorhamnolipids (mRL), produced by Pseudomonas aeruginosa ATCC 9027, and their mixtures with synthetic surfactants in order to postulate possible applications of these materials in industrial products and 2) examine the effects of mRL on commercial metal oxide nanoparticle (NP) aqueous dispersion behavior to reveal the potential impact of microbial secondary metabolites on NP fate and transport in the environment. The mixing behavior of mRL with cetylpyridinium chloride (CPC) was measured using surface tensiometry. Electrostatics resulted in cooperative enhancement in mixture properties, but were not significant until α(CPC) ≥ 0.25. Steady-state and time resolved fluorescence quenching measurements in mRL micelles revealed that quenching proceeded via a combined static and dynamic mechanism. Static quenching was preferred in mRL illustrating the reactants form a globular micelle. Changing the structure of the reactants displayed changes in the degree and mechanism of quenching further supporting this aggregate model. Fluorescence measurements on mRL-Tween 20 micelles supported that a geometrically-driven shape transition occurs as mRL decreases. The corresponding decrease in probe lifetime indicated the polarity of the micelle was decreasing. Tween "sealed" the mRL micelles making them less susceptible to water penetration. The effect of mRL on metal oxide NP dispersions was evaluated on adsorption strength, NP aggregate size and stability, and zeta potential under different conditions. Silica NPs showed little adsorption of mRL and was impervious to all variables in altering the solution stable aggregate size. NP aggregate size decreased at very high mRL concentrations due to osmotic and electrosteric repulsions of mRL micelles in solution. Titania, despite expectations, indicated fairly low adsorption of mRL and displayed similar aggregate dispersion stability as that of silica. Spectroscopic investigations exposed that the commercial titania NPs were contaminated with silica altering NP surface properties. Zinc oxide (ZnO) dispersions were substantially affected by the adsorption of mRL. Without mRL, ZnO NPs were unstable independent of pH. The addition of mRL stabilized the ZnO dispersions and lowered the zeta potentials. Furthermore, mRL coating prevented the dissolution of ZnO, the major factor implicated in ZnO toxicity.
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Kowada, Toshiyuki. "Studies on Synthesis and Properties of Heteroarene-Containing π-Conjugated Compounds Having Spirofluorene Moieties." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120879.
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Jones, Derek R. "Design, Synthesis, and Photophysical Properties of Corannulene-based Organic Molecules." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1323350004.
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Adhikari, Ravi M. "Carbazole-Based Emitting Compounds: Synthesis, Photophysical Properties and Formation of Nanoparticles." Bowling Green State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1224527666.
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Kubo, Hiromu. "Design and Synthesis of Helicene Derivatives with Excellent Chiroptical Properties." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263690.
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Ji, Botao. "Synthesis and optical properties of plasmonic fluorescent quantum dots." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066674/document.
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Grâce aux plasmons de surface des nanoparticules métalliques et aux propriétés optiques et électroniques des quantum dots (QDs), les nanostructures QD/métal suscitent beaucoup d'intérêt. Cependant, bien que prometteurs, les hybrides QD/or colloïdaux n'ont été que rarement obtenus.Nous avons mis au point la première méthode de synthèse généralisée conduisant à des structures hybrides cœur/coque/coque QD/SiO2/Au (appelées QDs dorés). Tout d'abord, les QDs hydrophobes sont encapsulés individuellement dans des billes de silice par émulsion inverse. Les nanoparticules obtenues sont ensuite recouvertes d'une coque d'or continue via un processus de dépôt en solution. Les épaisseurs de silice et d'or peuvent être ajustées indépendamment aux dimensions voulues. Nous avons montré que les QDs dorés individuels à base de QDs CdSe/CdS à coque épaisse possèdent une émission stable et poissonienne à température ambiante et sont très photostables. Cette nouvelle structure se comporte comme un résonateur plasmonique avec un facteur de Purcell élevé (~6), en très bon accord avec les simulations.Nous présentons également des auto-assemblages de QDs hydrophobes en superparticules (SPs). Un choix judicieux de QDs donne aux SPs des propriétés exceptionnelles telles qu'une émission de fluorescence intense, non-clignotante et multicolore. Des SPs multifonctionnelles peuvent aussi être obtenues en associant des nanocristaux magnétiques et fluorescents. La croissance d'une coque de silice sur les SPs a permis d'augmenter leur stabilité et nous avons démontré que cette couche de silice pouvait être recouverte d'une coque d'or pour améliorer la photostabilité et la biocompatibilité de ces SPsDue to the surface plasmons in metallic nanostructures and the exceptional optical and electrical properties of colloidal semiconductor quantum dots (QDs), QD/metal hybrid nanostructures attract much attention. However, although these structures are very promising, colloidal single QD/gold hybrids have rarely been synthesized.We managed to develop for the first time a generalized synthetic route to synthesize a QD/SiO2/Au core/shell/shell hybrid structure (golden QDs). First, hydrophobic QDs are individually encapsulated in silica beads via reverse microemulsion. The obtained QD/SiO2 nanoparticles are then coated with a continuous gold nanoshell using a solution deposition process. The thicknesses of the silica and the gold layers can be tailored independently to various dimensions. We showed that single golden thick-shell CdSe/CdS QDs provide a system with a stable and poissonian emission at room temperature and a high photostability. This novel hybrid golden QD structure behaves as a plasmonic resonator with a strong (~ 6) Purcell factor, in very good agreement with simulations. We also present the self-assembly of hydrophobic QDs into colloidal superparticles (SPs). With a fine choice of QDs, SPs could indeed possess outstanding properties including non-blinking fluorescence, high fluorescence intensity and multi-color emission. Multi-functional SPs could also be obtained by mixing fluorescent or magnetic nanocrystals. The subsequent growth of a silica shell on the SPs allowed an enhancement of their stability and we demonstrated this silica shell could itself be covered by a gold nanoshell to further improve the SPs photostability and biocompatibility
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Alajlouni, Ruba. "Membrane binding properties of Disabled-2." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/76980.
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Disabled-2 (Dab2) is an adapter protein that interacts with cell membranes and it is involved in several biological processes including endocytosis and platelet aggregation. During endocytosis, the Dab2 phosphotyrosine-binding (PTB) domain mediates protein binding to phosphatidylinositol 4,5-bisphosphate (PIP2) at the inner leaflet of the plasma membrane and helps co-localization with clathrin coats. Dab2, released from platelet alpha granules, inhibits platelet aggregation by binding to the °IIb? integrin receptor on the platelet surface through an Arg-Gly-Asp (RGD) motif located within the PTB domain. Alternatively, Dab2 binds sulfatides on the platelets surface, and this binding partition Dab2 in two pools (sulfatide and integrin receptor-bound states), but the biological consequences of lipid binding remain unclear. Dab2 binds sulfatides through two basic motifs located on its N-terminal region including the PTB domain (N-PTB). We have characterized the binding of Dab2 to micelles, which are widely used to mimic biological membranes. These micellar interactions were studied in the absence and presence of Dab2 lipid ligands, sulfatides and PIP2. By applying multiple biochemical, biophysical, and structural techniques, we found that whereas Dab2 N-PTB binding to PIP2 stabilized the protein but did not contribute to the penetration of the protein into micelles, sulfatides induced conformational changes and facilitated penetration of Dab2 N-PTB into micelles. This is in agreement with previous observation that sulfatides, but not PIP2, protect Dab2 N-PTB from thrombin cleavage. By studying the mechanism by which Dab2 targets membranes, we will have the opportunity to manipulate its function in different lipid-dependent biological processes.Master of Science
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Laszewski, Henryk. "Transfert thermique photo-induit par des nanoparticules d’or appliqué à la thérapie génique." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLN003/document.
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La thérapie génique est probablement une des approches la plus ambitieuse de l'histoire de l'humanité pour éliminer des maladies résistantes à tout autre traitement. Cependant, c'est une approche qui doit encore être développée afin d'obtenir un meilleur contrôle du processus de délivrance des médicaments et aussi de réduire les coûts. À cette fin, ce projet de thèse est axé sur l’optimisation et le contrôle de la délivrance d’oligonucléotides basée sur l'utilisation de nanobâtonnets d'or (Gold NanoRods, GNRs). De telles nanoparticules (40 nm de long et 10 nm de diamètre) sont internalisées par les cellules et grâce à leurs propriétés physiques extraordinaires permettent de délivrer les médicaments dans le cytoplasme de manière contrôlée. En effet, leur absorption très élevée dans le proche infrarouge du spectre électromagnétique permet de convertir l’énergie lumineuse en chaleur à l’intérieur et autour des nanobâtonnets, sans affecter la cellule. L’avantage d’une absorption dans l’infrarouge est qu’à cette longueur d’onde la lumière pénètre profondément dans les tissus humains (3 cm). Le contrôle de la température autour des nanoparticules permet la libération d'oligonucléotides par simple dénaturation du duplex à un instant donné.L’obtention de nanoparticules pouvant être considérées comme un « cargo » implique de remplir les conditions suivantes : stabilité de la forme colloïdale en milieu complexe, conservation des propriétés physiques et chimiques une fois administrées et possibilité d’immobiliser et de libérer le médicament de manière contrôlée.La première étape de mon projet a consisté à établir un protocole de synthèse de nanobâtonnets d’or afin d’obtenir une solution colloïdale mono-disperse et dont la bande d’absorption de plasmon longitudinal soit dans le proche infrarouge. L'étape suivante était d’optimiser un protocole de fonctionnalisation de la surface des GNRs. Le défi ici est associé à l'agrégation des GNRs lorsque le surfactant (CTAB) nécessaire au maintien des GNRs en solution est remplacé par des biomolécules (oligonucléotides). Cependant, après une étude systématique et détaillée, la déstabilisation de la couche protectrice de surfactant sur la surface métallique et l’ajout d’oligonucléotides ayant une fonction thiol à une des deux extrémités dans un rapport approprié ont permis une bio-fonctionnalisation efficace des nanobâtonnets. En conséquence, les nanoparticules fonctionnalisées, après redispersion dans la solution, ont les propriétés physico-chimiques nécessaires. En outre, l’immobilisation des oligonucléotides sur la surface des nanoparticules est spécifique (via la liaison thiol-Au) et permet leur transfert dans des solutions tamponnées ou dans des milieux complexes sans affecter leur stabilité. Après hybridation entre le simple brin immobilisé sur la surface des nanobâtonnets et le brin complémentaire, j’ai démontré que les oligonucléotides étaient stables et que le nombre de doubles brins qui se forment par hybridation peut être contrôlé. L’analyse des propriétés des nanomatériaux a constitué la seconde étape clé de mon travail, car elle revêt une importance cruciale pour la délivrance contrôlée de médicaments. J'ai décidé d'appliquer des méthodes uniquement optiques couvrant l'absorption des nanobâtonnets et l'analyse de la fluorescence des oligonucléotides marqués et des images TEM.Au cours du projet, il a donc été possible d’établir une nouvelle approche de fonctionnalisation et de créer un protocole de caractérisation efficace, axé sur les oligonucléotidesGene therapy is probably one of the most ambitious approaches in human history that aims to eliminate diseases, often those completely resistant to other treatments. However, this approach requires further development in order to obtain better control over the process of drug delivery and reduce costs. For this purpose, this project has focused on delivery of oligonucleotides using gold nanorods (GNRs). Such nanoparticles, (40 mm in length and 10 nm in diameter) can be internalized by cells and their extraordinary physical properties allow the delivery of drugs to the cytoplasm of cells in a controlled manner. Indeed, their strong absorption in the near-infrared part of the electromagnetic spectrum allows conversion of the energy of light into heat around the nanorods without affecting the cells. The advantage of absorption in the infrared is that at this wavelength the light can penetrate human tissues (3 cm). Control of the temperature around the nanoparticles allows the release of oligonucleotides by simple denaturation of the duplex at a given time.Obtaining nanoparticles that can be considered as a "cargo ship" implies fulfilling the following conditions: stability of the colloidal form in a complex medium, preservation of the physical and chemical properties once administered and the ability to immobilize and release the drug in a controlled manner.The first step of my project was to establish a nanorods synthesis protocol in order to obtain a monodisperse colloidal solution whose longitudinal absorption band is in the near infrared. The next step was to optimize the functionalisation protocol of the surface of the GNRs. The challenge here is associated with the aggregation of GNRs when the surfactant (CTAB) needed to maintain the GNRs in solution is replaced by biomolecules (oligonucleotides). However, after a systematic and detailed study, the destabilisation of the surfactant protective layer on the metal surface and the addition of oligonucleotides having a thiol function at one of the two extremities in a suitable ratio allowed an efficient bio-functionalisation of the nanoparticles. As a consequence, the functionalised nanoparticles, after redispersion in solution, possess the necessary physicochemical properties. In addition, the immobilisation of oligonucleotides on the surface of the nanoparticles is specific (via the thiol-Au bond) and allows their transfer into buffered solutions or in complex media without affecting their stability. After hybridisation between the single strand immobilized on the surface of the nanorods and the complementary strand, I demonstrated that the oligonucleotides were stable and that the number of double strands that are formed by hybridization can be controlled. The analysis of the properties of nanomaterials was the next important part of the work, as it is of crucial importance for the controlled delivery of drugs. I decided to apply only optical methods covering nanorods absorption and fluorescence analysis of labeled oligonucleotides and TEM images.In summary, during the project it was possible to establish a new functionalization approach and create a protocol for efficient characterization, focused on oligonucleotides. We expect that these observations will aid further research in the field of gene delivery based on gold nanoparticles