Tesis sobre el tema "Résonance de réseau de surface"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Résonance de réseau de surface".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
Jimenez, Alvaro. "Une biocapteur à base de résonance de plasmons de surface intégré monolithiquement avec une source d'excitation". Thèse, Université de Sherbrooke, 2015. http://hdl.handle.net/11143/8178.
Texto completoKhourdifi, Miloudi. "Influence de la présence d'inhomogénéités (surface, interface, défaut plan) sur les vibrations acoustiques transverses dans un super-réseau". Mulhouse, 1990. http://www.theses.fr/1990MULH0151.
Texto completoBrenet, Sophie. "Développement et optimisations d'un nez électronique basé sur l'imagerie de résonance de plasmons de surface". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY089.
Texto completoElectronic noses are promising candidates for low-cost field monitoring of volatile organic compounds (VOCs). However, these techniques are still challenged with limitations. The use of a limited number of receptors prevents selective VOCs differentiation. A lack of reliability caused by pollution of receptors hinders their use for many applications. In this context, an electronic nose based on surface plasmon resonance imaging (SPRI) is developed for the detection of VOCs in the gas phase. This system consists of a broad array of receptors obtained by the self-assembly of organic molecules and peptides. SPRI optical transduction provides multiplexed monitoring of a large number of interactions in real time. The objective is to ensure the best possible chemical resolution to reliably differentiate VOCs. To this end, different strategies are explored to improve the sensitivity, selectivity and stability of the measurements. Thanks to these optimizations, our system offers a high selectivity for a large number of VOCs. VOCs are differentiated according to their chemical nature and structure. A good repeatability and a stability of at least two months are obtained. Preliminary tests show that our instrument is also effective for the analysis of more complex samples
Chamtouri, Maha. "Etude exhaustive de la sensibilité des Biopuces plasmoniques structurées intégrant un réseau rectangulaire 1D : effet de la transition des plasmons localisés vers les plasmons propagatifs". Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112060/document.
Texto completoSurface plasmons resonance imaging with continuous thin metallic films have become a central tool for the study of biomolecular interactions. However, in order to extend the field of applications of surface plasmons resonance systems to the trace detection of biomolecules having low molecular weight, a change in the plasmonic sensing methodology is needed. In this study, we investigate theoretically and experimentally the sensing potential of 2D nano- and micro- ribbon grating structuration on the surface of Kretschmann-based surface plasmon resonance biosensors when they are used for detection of biomolecular binding events. Numerical simulations were carried out by employing a fast and novel model based on the hybridization of two classical methods, the Fourier Modal Method and the Finite Element Method. Our calculations confirm the importance of light manipulation by means of structuration of the plasmonic thin film surfaces on the nano- and micro- scales. Not only does it highlight the geometric parameters that allow the sensitivity enhancement, and associated figures of merit, compared with the response of the conventional surface plasmon resonance biosensor based on a flat surface, but it also describes the transition from the regime where the propagating surface plasmon mode dominates to the regime where the localized surface plasmon mode dominates. An exhaustive mapping of the biosensing potential of the nano- and micro- structured biosensors surface is presented, varying the structural parameters related to the ribbon grating dimensions. New figures of merit are introduced to evaluate the performance of the structured biosensors. The structuration also leads to the creation of regions on biosensor chips that are characterized by strongly enhanced electromagnetic fields. New opportunities for further improving the bio-sensitivity are offered if localization of biomolecules can be carried out in these regions of high electromagnetic fields enhancement and confined
Bavard, Alexis. "Nanostructuration de surface de plaques de silicium (001) par révélation d'un réseau de dislocations enterrées pour l'auto-organisation à longue distance de nanostructures". Phd thesis, Grenoble 1, 2007. http://www.theses.fr/2007GRE10144.
Texto completoLn order to carry on the trend of optical and electronical devices dimensions shrinking, nanostructures are expected to be an alternative solution to convention al microelectronics technology. Nevertheless, to be exploited, the size, density and positioning of these nanostructures have to be accurately controlled. To avoid time consuming solutions, collective growth is privileged and long range positional order displays in general only if the surface is first prepared. Ln this framework, we developed a nanopatterned substrate by revealing of a buried dislocations (20) regular network elaborated by direct twist bonding of (001) silicon wafers. Use of preferential chemical etching has been optimized to reveal dislocations lines creating at the surface a square network of silicon nano-dots disjointed by nano-trenches more or less deep. This kind of template has been tested to induce a long range positional order of Ge dots and metalli nanoparticles (Ni, Au, Ag). We shown that self-organization of these nanostructures was possible only if the energetic barrier induced by trenches depth was large enough to prevent the kinetic effects. Ln these conditions, self-assembled Ge islands have been analyzed by X¬rays methods and metallic nanoparticles by plasmon resonance
Bavard, Alexis. "Nanostructuration de surface de plaques de silicium (001) par révélation d'un réseau de dislocations enterrées pour l'auto-organisation à longue distance de nanostructures". Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00185768.
Texto completoCollin, Stéphane. "Résonances photoniques dans les réseaux métalliques : théorie et application à la photodétection ultrarapide". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2002. http://tel.archives-ouvertes.fr/tel-00142103.
Texto completoNous avons mis en oeuvre un calcul original des courbes de dispersion complexes des réseaux métalliques, basé sur une méthode modale et un formalisme de matrice S. Le calcul des structures de bandes photoniques complexes et de la répartition spatiale du champ électromagnétique a permis de décrire précisément les résonances de surface horizontales et verticales, leurs conditions d'excitation ainsi que leurs durées de vie radiatives et non radiatives. Leurs propriétés de confinement et de transmission de la lumière dans des fentes très fines devant la longueur d'onde offrent de nouvelles possibilités en optoélectronique.
Nous proposons en particulier deux structures de type métal-semiconducteur-métal pour la photodétection ultrarapide, dans lesquelles le confinement de l'absorption permet de repousser le compromis habituel entre rendement et vitesse. La première structure est un réseau métal/semiconducteur dans lequel la lumière est absorbée entre les électrodes. La seconde structure permet une absorption efficace dans une fine couche sous le réseau métallique. Ces deux photodétecteurs, dont la distance inter-électrode est d'environ 100 nm, ont été fabriqués sur substrat de GaAs. Le bon accord des mesures de réflectivité et de photocourant avec la théorie a permis de valider cette approche, qui pourra notamment être appliquée aux longueurs d'onde des télécommunications.
Les dimensions mises en jeu rendent possibles des fréquences de coupure de plusieurs centaines de GHz, avec un rendement théorique de 75 % indépendamment de la polarisation de la lumière. Ces résultats ouvrent la voie à une nouvelle génération de photodétecteurs ultrarapides.
Ahmidayi, Najat. "Déformations de systèmes plasmoniques : application aux nanocapteurs de déformations". Electronic Thesis or Diss., Université de Lille (2022-....), 2024. http://www.theses.fr/2024ULILN022.
Texto completoBased on the exploitation of the optical properties of metallic nanoparticles in combination with flexible materials, plasmonomechanics has recently emerged as a subfield of nano-optomechanics. Plasmonomechanical systems, which enable the measurement of mechanical strains applied to flexible substrates through the plasmonic response of nanostructures, have attracted much attention in the scientific research community due to their potential applications, notably in strain detectors.Understanding the microscopic mechanical response to macroscopic deformation is a foundation of plasmonomechanics, essential for comprehending the optical response of nanostructures and its evolution. The first objective of this thesis is to understand, through numerical simulation tools, the mechanical and plasmonic responses, and more precisely, how interparticle distances evolve at the nanometric scale when macroscopic mechanical strain is imposed and influence the plasmonic response of the system. This will be studied through simple plasmonomechanical systems composed of gold nanodimers deposited on a PDMS membrane.Another challenge in this field is the design of plasmonomechanical systems with high sensitivity to mechanical deformations. This can be achieved through plasmonic systems supporting resonance modes with minimal losses (narrow linewidth). Thus, the second objective of this thesis is to realize plasmonomechanical systems supporting resonances such as the Fano resonance in a rod-disk system and the surface lattice resonance in a 2D array of gold nanorings, both known for their sharp and narrow resonance profiles
Salvaggio, Ermelinda. "Nanoparticles of Nitride-based Materials for Plasmonics and Lossy-mode Resonance". Electronic Thesis or Diss., Troyes, 2022. http://www.theses.fr/2022TROY0011.
Texto completoIn this manuscript, we study different transition metal nitrides (TiN, ZrN and HfN) whose properties and optical characteristics are related to their composition, dielectric environment, size and shape. We describe the sputtering technique used to deposit nitride films on silicon (111) and fused silica substrates. The x-ray diffraction measurements show the crystal structures of the films and give a measure of their grain size as the nitrogen flux varies. The x-ray reflectometry gives a measurement of density, thickness and roughness of the films. The atomic force microscopy, allows a characterization of the surface roughness. The ellipsometry provides refractive indices and extinction coefficients that will be used to extract the Faraday and Joules numbers. The spectrophotometric measurements provide transmission spectra used to derive the optical band gap energies. From nitride thin films, we fabricated arrays of nanoparticles with controlled shape, size and period using the EBL technique.Their extinction spectra clearly show that the resonance peaks strictly depend on the size, shape, stoichiometry and period of the nanoparticles array.The measured extinction spectra are compared to those simulated using FDTD method and they show that there is a good agreement between experimental measurements and simulations. We thus demonstrated the interest of using these materials as alternatives to the noble metals conventionally used in plasmonics
Faye, Clément. "Le réseau d'interactions de l'endostatine, une matricryptine du collagène XVIII". Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10176.
Texto completoEndostatin is the carboxyl-terminal fragment of collagen XVIII released in the extracellular matrix by proteolytic cleavage. It inhibits angiogenesis and tumor growth. Endostatin inhibits the proliferation and migration of endothelial cells induced by Fibroblast Growth Factor-2 and Vascular Endothelial Growth Factor and it inhibits 65 different tumor types. Endostatin is currently under clinical trials for several tumors. We have used surface plasmon resonance (SPR) binding assays to characterize interactions between endostatin and α5β1 or αvβ3 integrins which are over-expressed at cell surface of actived endothelial cell. We have identified the binding site of endostatin on those integrins, and we have built a molecular modeling of the endostatin/integrin αvβ3 complex. We have shown that endostatin can not bind simultaneously to integrins and to heparan sulfate. In order to identify new partners of endostatin we have developed glycosaminoglycan and protein arrays based on SPR detection. We have found nine new partners of endostatin include glycosaminoglycans (chondroitin and dermatan sulfate), matricellular proteins (thrombospondin-1 and SPARC), collagens (I, IV and VI), the amyloid peptide Aβ(1-42), and transglutaminase-2 (TG-2). We have shown that endostatin binds to transglutaminase-2 with an high affinity (KD ~ 6 nM) in a calcium-dependent manner. Enzymatic assays indicated that, in contrast to other extracellular matrix proteins, endostatin is not a glutaminyl substrate of TG-2, but would rather be an acyl acceptor. The endostatin network comprises a number of extracellular proteins containing EGF domains (Epidermal Growth Factor), and able to bind calcium. Depending on the trigger event, and on the availability of its members in a given tissue at a given time, the endostatin network might be involved either in the control of angiogenesis, and tumor growth, or in neurogenesis and neurodegenerative diseases
Guiset, Pierrick. "Contrôle optique des cathodes froides à base de nanotubes de carbone pour les sources THz". Phd thesis, Ecole Polytechnique X, 2010. http://pastel.archives-ouvertes.fr/pastel-00543060.
Texto completoColas, Florent. "Propriétés optiques et thermoplasmoniques de réseaux de nanocylindres : applications à la détection de molécules et de micro-objets". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCD039/document.
Texto completoRaman spectroscopy is a technique that is non-invasive, non-destructive, allowing the identification of the molecules contained in a solid, liquid or gaseous sample. However it suffers from one major drawback : low sensitivity. This limit is now about to be pushed through the fast growth of SERS (Surface Enhanced Raman Scattering). This phenomenon has been already implemented successfully in various applications : biomedical, biology, analytical chemistry,environmental science... However, despite a growing number of scientific works, some aspects of the SERS sensors still need to be studied. This work focused on the study of the near-field and the far-field properties of arrays of nanocylinders for the detection of organic compounds. The studied parameters are the period of the array, the diameter of the cylinders, but also the material constituting the nanoparticle as the adhesion layer. The study of optical properties naturally led us to investigate the phenomenon of absorption. The incident light energy is converted into heat. The nanocylindres then behave like nanosources of heat. Thus, part of this work focused on the effects of thermoplasmonics. One of the applications that we demonstrated is the ability to manipulate the micro-objets, thanks to the control of the phenomena of advections
Salza, Romain. "Les réseaux d’interactions de l’endostatine, de l’angiogenèse à la maladie d’Alzheimer". Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10119.
Texto completoThe extracellular matrix include approximately 300 proteins and proteoglycans which constitute the matrisome and 800 associated proteins (Naba et al., 2012a) and glycosaminoglycans. It is an under-explored proteome which is modified in many diseases. Extracellular matrix bioactives fragments (matricryptins) are able to regulate physiopathological process like angiogenesis and cerebral disorders (Ricard-Blum and Salza, 2014). About 90 % of patients with Alzheimer's disease (AD) have cerebral amyloid angiopathy. Angiogenesis contributes to the development of AD. We are studying endostatin (ES), a matricryptin of collagen XVIII which has anti-angiogenic and anti-tumoral activities and is also present in amyloid plaques in AD patients. ES is released by neurons and is able to form amyloid fibrils in vitro (Kranenburg et al., 2003). This anti-angiogenic matricryptin could therefore be involved in AD. We have shown that ES is present in the cerebrospinal fluid of AD patients and the ratio of its concentrations to conventional markers of AD improves the diagnosis of patients with frontotemporal dementia (FTD) and discriminate AD patients from those suffering from FTD and pathology noAD/noDFT. We have established the extracellular interactions repertoires of the -amyloid peptide (1-42) in monomeric, oligomeric, fibrillar or aggregated forms and showed that the oligomerization and fibrillogenesis increase the interaction capacity of the -amyloid peptide. We have established the global interaction network of endostatin by surface plasmon resonance imaging and identified 21 new partners of this matricryptin. Specifically, we characterized its interaction with the Procollagen C-Proteinase Enhancer-1, a protein which gives rise to an anti-angiogenic matricryptin. We finally built networks of specific extracellular interactions of angiogenesis and of Alzheimer's disease and amyloid process to identify proteins connecting these two processes that are potential therapeutic targets. These interaction networks have been built using 239 interactions including those we have identified experimentally and those described in the literature. This data will be available in the database specific of extracellular interactions created in the laboratory, MatrixDB, in the new version of which we contributed
Vega, Marlo. "Étude expérimentale et théorique des effets photo-thermiques ultra-rapides dans des réseaux de nanoparticules - application au contrôle local de la chimie de surface". Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPAST081.
Texto completoThe excitation of metal nanoparticles through short pulses of lightinduces localized photo-thermal effects capable of altering their surface chemistry. Thisresearch aims to investigate and harness these effects for the precise manipulation ofmolecule distribution on nanoparticles at a local level. Initially, employing both pumpprobespectroscopy measurements and a thermo-optical numerical model with minimalfree parameters, we outlined the heterogeneous nature of photo-thermal effects withinasymmetric cross-shaped nanostructures. Then, a methodology was developed tospecifically label the surface chemistry using silica nanoparticles. This labelingrevealed the localized degradation of molecules on the nanostructure's surface exposedto very short pulses. Under low-power illumination, only molecules within highelectricfield zones undergo degradation, enabling the experimental delineation andvisualization of electric field intensity distribution on the structure surfaces with a fewtens of nanometers resolution. These findings pave the way for the development ofplasmonic sensors optimized for the detection of molecules at very low concentrations
Lepinay, Sandrine. "Développement de couches polymères nanométriques pour l'immobilisation de récepteurs naturels et le design de récepteurs synthétiques sur des transducteurs optiques". Thesis, Paris Est, 2011. http://www.theses.fr/2011PEST1099.
Texto completoTo answer to an always increasing request in sensors, optical measurement systems allowing the detection of natural or synthetic receptors on inorganic substrates were elaborated. By Plasmon Surface Resonance (SPR), we showed that thin films constituted with copolymers of N-(acryloxysuccinimide) and poly (ethylene glycol) acrylates derivatives or that a thin film of polyglycidol presented a strong resistance in non-specific protein adsorption and that they allowed a covalent grafting of biomolecules through their respective reagent groupings. A new sensor, a tilted fiber Bragg gratings was then developed and characterized by using multilayers films presenting selective and reversible properties of recognition by forming inclusion complexes between polymers of cyclodextrine and adamantine derivatives. From this optical fiber, it was also possible to follow in real time interfacial conformation transition, according to the pH, of poly(acrylic acid) chains immobilized covalently on the substrate. For both approaches, biosensors for the detection of bovin serum albumin (BSA) were realized. Furthermore, the inclusion properties of cyclodextrine compounds allowed also the complexation of small hydrophobic molecules such as toluene, which forming chemical sensors. Finally, to avoid the use of a biological material, molecular imprinted polymers (MIP) were also developed. Their selectivity, specificity and sensibility toward gallic acid, the target molecule, were estimated by cyclic voltammetry. The results confirm that these polymers can be considered as artificial receptors
Fevrier, Mickaël. "Couplage entre un guide d’onde diélectrique et un guide à plasmon de surface localisé : conception, fabrication et caractérisation". Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112040/document.
Texto completoThis PhD work presents a theoretical, numerical and experimental study of the integration of a gold nanoparticle chain supporting "localized surface plasmon resonances" on a dielectric waveguide. The localized surface plasmon allows a sub-wavelength confinement of light which could lead to the achievement of ultra-compact optical components. However, the high level of optical losses restricts their application to short propagating distances unlike dielectric waveguides. A judicious combination of both types of guides should therefore allow taking profit of their respective advantages. Firstly, we have theoretically studied the properties of nanoparticles chains using an analytical model that we have developed following the coupled dipoles approximation. This has helped us to determine the shape and size of nanoparticles, which have been further used in a FDTD software, to simulate the coupling between the chain and the dielectric waveguide (SOI or Si3N4). Using this numerical study, we have deduced the geometries of structures to be fabricated. The realized structures have been characterized using a spectrally resolved transmission set-up, built during this thesis, and an optical near field measurement set-up (collaboration LNIO Troyes). For the first time, we have experimentally shown the properties of short nanoparticle chains integrated on a SOI waveguide as well as the existence of a coupled waveguide phenomenon between long nanoparticle chains and SOI waveguides. A record value has been obtained for the coupling constant at telecom wavelengths (near infrared). The light energy carried by the TE mode of the SOI waveguide can be completely transferred into the plasmonic waveguide via the first 4 or 5 nanoparticles of the chain, which means a distance of less than 600 nm. We have also studied the properties of Bragg gratings based on localized surface plasmon. Experimental results from spectrally resolved transmission measurements have been compared to theoretical results obtained from an analytical model based on the point dipole approximation in quasi-static regime, on one hand, and using the coupled mode theory, on the other hand. This work opens the way for applications to optical tweezers, sensors or spasers, which will benefit from the integration of metal nanoparticles in photonic circuits
Andrianandrasanirina, Tinasoa Faly. "Nanophotonique : guidage d'ondes sur des surfaces structurées". Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2010. http://tel.archives-ouvertes.fr/tel-00662447.
Texto completoIbrahim, Elmi Omar. "Nouvelles structures de cellules solaires à base de silicium : texturation, passivation et association de réseaux de nanostructures métalliques avec une couche Down-Conversion". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10037/document.
Texto completoThe viability of the silicon sector for the photovoltaic conversion is not any more in demonstrated, in particular with regard to the increasing number of industries of solar cells which become established in the developed countries. To obtain a large absorption of the light, the development of new structures or optical devices to improve the light trapping within solar cells is a real challenge. The works of this thesis concern a new generation of solar cells on the association of a network of metallic nano-objects and rare earth within a SiNx matrix. At first, we optimized two forms of textures on the surface of the silicon which increased the absorption in 15 % for the forms with nanopillars and 28 % for nanocones. The etching process of the silicon engenders the appearance of defects on the surface. We worked on three approaches of the surface passivation using thin layers of Al2O3 and SiNx materials to limit the phenomena of recombination. The second step of these works concerned the study of the plasmonics of a silver nanoparticles arrays fabricated through auto-assembled silica microspheres deposited by the Langmuir-Blodgett technique. The incorporation of silver nanoparticles in the matrix increased significantly our solar cells efficiency. In the last part, we studied the association of these metallic nano-objects with a layer down-conversion established of a matrix SiNx with rare earth Tb3+ and Yb3+. This association showed an increase of the intensity of photoluminescence of a factor 2,3. The application of the DC layer alone on our cells increased the efficiency of a factor 1,68
Ushkov, Andrei. "Extraordinary optical transmission in holographic and polycrystalline diffractive nanostructures". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSES026.
Texto completoThe thesis is devoted to the Extraordinary Optical Transmission observed in diffractive systems. An industrial need in integration and miniaturization of optical components stimulates the development of planar grating-based devices with thicknesses comparable to operating wavelengths. The EOT effect is perspective for plasmonic applications in structure-induced colors, optical filtering, lasing, optical biosensors due to the improved signal-to-noise ratio and a simplified device design. Aimed at practically available materials and industrially-compatible surface nanotexturing methods, a systematic study of EOT through continuous aluminum films was performed. A modification of laser interference lithography allowing rapid fabrication of variable depth gratings was proposed, theoretically established and experimentally validated. The variable depth defines the efficiency of plasmonic coupling at a fixed wavelength, offering additional possibilities for light manipulations. Using this approach the existence of optimal grating depth for EOT was demonstrated experimentally and depth-resolved structure-induced colors were observed in transmission. For the first time the effect of EOT was experimentally measured in polycrystalline samples, fabricated via nanosphere photolithography. A phenomenological model of EOT in polycrystaline structures and a dimensionless coefficient of disorder are proposed to explain measured transmission curves. The grating depth and disorder concurrence was studied numerically. The systematic study of EOT in various diffraction systems presented in this thesis might pave the way towards more effective plasmonic devices and industrial applications
Kriegl, Roberta. "A flexible coil array for high resolution magnetic resonance imaging at 7 Tesla". Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112425/document.
Texto completoMagnetic resonance imaging (MRI), among other imaging techniques, has become a major backbone of modern medical diagnostics. MRI enables the non-invasive combined, identification of anatomical structures, functional and chemical properties, especially in soft tissues. Nonetheless, applications requiring very high spatial and/or temporal resolution are often limited by the available signal-to-noise ratio (SNR) in MR experiments. Since first clinical applications, image quality in MRI has been constantly improved by applying one or several of the following strategies: increasing the static magnetic field strength, improvement of the radiofrequency (RF) detection system, development of specialized acquisition sequences and optimization of image reconstruction techniques. This work is concerned with the development of highly sensitive RF detection systems for biomedical ultra-high field MRI. In particular, auto-resonant RF coils based on transmission line technology are investigated. These resonators may be fabricated on flexible substrate which enables form-fitting of the RF detector to the target anatomy, leading to a significant SNR gain. The main objective of this work is the development of a flexible RF coil array for high-resolution MRI on a human whole-body 7 T MR scanner. With coil arrays, the intrinsically high SNR of small surface coils may be exploited for an extended field of view. Further, parallel imaging techniques are accessible with RF array technology, allowing acceleration of the image acquisition. Secondly, in this PhD project a novel design for transmission line resonators is developed, that brings an additional degree of freedom in geometric design and enables the fabrication of large multi-turn resonators for high field MR applications. This thesis describes the development, successful implementation and evaluation of novel, mechanically flexible RF devices by analytical and 3D electromagnetic simulations, in bench measurements and in MRI experiments
Zakaria, Abdoul mouize. "Réseaux ordonnés de nanoparticules étudiés par la combinaison de microscopie STM et spectroscopie SFG". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS143/document.
Texto completoThis manuscript describes the development of a dense and ordered network of epitaxially grown nanoparticles on an oxide thin-film (Al₂O₃) prepared on a Ni₃Al (111) crystal. Pd nanoparticles, and nanoparticles with palladium core and gold shell, were made with a narrow size distribution, thanks to the fact that the nucleation centers are regularly spaced. The thin oxide layer and then the nanoparticle network are studied by STM microscopy according to the substrate oxidation and Pd deposition parameters, in particular the oxidation and annealing temperatures, and the flow of palladium atoms. Beyond 1 ML of Pd and 1 ML of gold, the network becomes progressively disordered.In addition to STM microscopy, the small size distribution makes it possible to study the nanoparticles by means of overall spectroscopic measurements: the sum frequency generation (SFG) vibrational spectroscopy is used to characterize the distribution of the adsorption sites according to the size and chemical nature of the nanoparticles; differential reflectance spectroscopy (DRS) is used to characterize plasmonic properties. SFG discriminates between facet and edge sites, allowing to show that the nanoparticles grow rapidly in height. On core-shell particles, SFG allows to observe the segregation of Pd atoms across the gold shell, with Pd and gold sites distinguished by CO frequency. CO is selectively adsorbed on Pd atoms at moderate pressure (less than 10-3 mbar), then also on Au atoms at high pressures (1 mbar). Moreover, at high pressure CO induces the thermally reversible segregation of a large number of Pd atoms.The DRS makes it possible to observe the appearance of a plasmon resonance for a shell wider than 3 ML of gold. The resonance is more intense as the core of Pd is small, and the shell thick. But only becomes really intense in the vicinity of the coalescence of NPs.These experiments pave the way for finer experiments, in particular to probe more precisely the properties as a function of size, or the adsorption of CO in the presence of oxygen. They also open the way for the subsequent study of the adsorption of organic molecules on the nanoparticle network. The adsorption of molecules in bridge between nanoparticles will be sought. The electron transfer in the hybrid network thus formed will be studied using pump-probe experiments where electrons will be excited in the nanoparticles. SFG will probe the transient state of molecules under the effect of charge transfer
Banville, Frédéric. "Nanostructuration de surface pour l'imagerie à résonance de plasmons de surface de haute résolution". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLO005/document.
Texto completoIn pharmacological research, living cells are widely used as the sensing medium for biological studies, such as cell apoptosis and cellular reorganization. Different characterization systems are developed to analyze and quantify biological information. Surface plasmon resonance (SPR) imaging is sensitive to minute refractive index variations occurring in a medium at the proximity of a metal layer. It has found many applications in pharmacological research since it allows the real-time image acquisition and does not require biological labeling like for fluorescence. However, the propagative nature of surface plasmons (PSPs) limits the spatial resolution by spreading the information in the direction of propagation of the PSPs. This means that it is difficult to spatially resolve details smaller than the attenuation length of the PSPs, generally of the order of tens of micrometers. Several research groups have worked on this limitation in order to improve the spatial resolution in SPR imaging. However, although spatial resolutions lower than that of the propagation have been obtained, those techniques require compromises, such as loss in temporal resolution or in refractive index.In this thesis project, plasmonic devices were designed and characterized in order to improve spatial resolution in SPR imaging, while minimizing compromises with other imaging parameters. These SPR chips are composed of nanostructured metal surfaces where the guided mode combines the properties of propagative plasmons and localized plasmons. An in-house numerical modeling software has demonstrated how the geometry of nanostructured surfaces can be optimized to reduce the attenuation length of the plasmonic mode, while maintaining a high imaging contrast. An optimum geometry was identified, and micron-sized structures have been observed using the optimized nanostructured SPR chips. Experimental results showed a reduction in propagation by a factor of 6.3 compared to uniform metal surfaces.The imaging performances of nanostructured SPR chips were assessed by studying cellular responses following pharmacological stimulation. The chips were used in real-time monitoring of integrity changes in confluent endothelial cell layer following stimulation. Quantification of intercellular gaps in the monolayers showed a significant increase in the number of small holes detected (~ 1μm2) when using nanostructured SPR chips. This increase in sensitivity to cellular activity is the result of improved spatial resolution. Finally, the study of morphology in highly linear cytoskeleton cell enabled the observation of subcellular structures and the monitoring of cytoskeleton reorganization in individual cells. The nanostructured SPR chips designed and realized during this thesis show a strong potential label-free live cell imaging
Sauvage-Vincent, Jean. "Les modes de plasmon sur film métallique ondulé, appliqués aux documents de sécurité". Phd thesis, Université Jean Monnet - Saint-Etienne, 2013. http://tel.archives-ouvertes.fr/tel-01068070.
Texto completoMassenot, Sébastien. "Étude, modélisation et réalisation de composants diffractants : contribution à l'étude de matériaux accordables et application à l'enregistrement holographique de filtres résonants". Télécom Bretagne, 2006. http://www.theses.fr/2006TELB0007.
Texto completoThis thesis is in keeping with the research activities of the optics department of the ENST Bretagne concerning optical information processing functions. This work is based on the study of 1D or 2D diffraction gratings realized holographically in order to obtain functions such as Bragg gratings or resonant optical filters. Suitable simulation tools are developed to determine the theoretical response of these structures: the rigorous coupled-wave theory and the differential method, which take the vector nature of light into account. Two holographic materials used for recording volume holograms are studied: Dupont photopolymers for which a diffusion model is established and H-PDLCs (Holographic Polymer Dispersed Liquid Crystals) which can be used to realize electrically switchable Bragg gratings. These studies concerning modelling and recording materials allow us to validate the principle of two resonant optical filters. The first filter is a 2D photonic crystal made of two orthogonal periodic structures. The filtering operation is due to the enhancement of the diffraction by the structure when the incident light is at the photonic band-edge. The second resonant filter is tunable and uses surface plasmon resonance phenomena occurring for metallic surface relief gratings, the tunability being provided by the PDLC material
Schiavoni, Michèle. "Dynamique des atomes dans un réseau optique dissipatif : modes de propagation, résonance stochastique, diffusion dirigée". Palaiseau, Ecole polytechnique, 2003. https://pastel.archives-ouvertes.fr/tel-00003129.
Texto completoMougenot, Charles. "L'asservissement par IRM d'un réseau matriciel ultrasonore et ses applications thérapeutiques". Bordeaux 1, 2005. http://www.theses.fr/2005BOR13121.
Texto completoChevalier, Sylvain. "Etude de couches structurées à base d’azopolymères pour l’optique diffractive et plasmonique photo-modulable". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLX057/document.
Texto completoTrans-cis photo-isomerization of azobenzene units generate mechanical work on its hosting matrice, allowing matter migration inside. This property allows to optically pattern micro and nanometric structures at the surface of azobenzene-containing materials (polymer, glass). Such phenomena were widely investigated and exploited to produce tunable devices exploiting photo-mechanical properties of azobenzene molecules.The purpose of this thesis were to fabricate metal-dielectric azobenzene-containing micro and nanostructured gratings and study the evolution of their optical and plasmonic properties under light stimulation.First, we developped a structuration methode inspired from solvent-assisted nanoimprint lithography to generate 2D azobenzene-gratings of pillars. Type and direction of the deformation induced in the structures were directly associated with the stimulation light polarization. Reversibility of the deformation were observed for a certain type of illumination cycle. Modification of the optical properties (transmission, diffraction) was investigated during the deformation of the pillars.Then, gratings were covered with tens of nanometers of gold. Metallization did not affect the deformation of the structures. Study in the visible range shows that interferences in the reflection spectra vanishes during the photo-deformation. In the infrared domain, the deformation leads to a strong modification of the plasmonic properties, enhancing particular plasmonic modes in favor of others. Control of the grating pillars shape allows a precise tenability of optical and plasmonic properties of the hybrid device
Élisabelar, Christian. "Structures et techniques de contrôle des convertisseurs connectés à un réseau triphasé impédant". Toulouse, INPT, 1990. http://www.theses.fr/1990INPT013H.
Texto completoBaril, Nathalie. "RMN dans un gradient d'induction oscillante : de l'imagerie de surface à la détection de mouvements". Bordeaux 1, 2002. http://www.theses.fr/2002BOR12570.
Texto completoJimenez, Alvaro. "Développement de nanoréseaux pour un biocapteur de résonance par plasmons de surface". Mémoire, Université de Sherbrooke, 2008. http://savoirs.usherbrooke.ca/handle/11143/1457.
Texto completoSereda, Alexandra. "Imagerie multi-spectrale par résonance des plasmons de surface : développement et applications". Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112321/document.
Texto completoBiodetection is at the core of the current health concerns, as shown through the variety of applications to HIV screening, food contaminant analysis or water quality monitoring. In this field, plasmonic biosensing is a well-established label-free technique on the market: commercial systems from HORIBA Scientific are currently available for both research and industrial users.Based on the surface plasmon resonance (SPR) phenomenon, plasmonic biodetection uses the high sensitivity of an evanescent wave propagating along a metallic film (forming the biochip) and the surrounding dielectric medium interface. More specifically, the adsorption of biomolecules onto the metal surface induces a strong change in the optical properties of a light beam reflected by the biochip: the main principle of plasmonic transduction consists in measuring these physical changes. Several interrogation techniques have therefore been developed to access such optical information, but they fail in meeting the most demanding user requirements for precise, real-time, high-throughput measurement.Initiated by these issues, the instrumentation work presented in this document has led to the development of a novel SPR interrogation technique, referred to as multi-spectral interrogation. Moreover, the promising results obtained have been pushed forward to propose a multi-spectral illumination system based on LEDs, providing attractive performances compared to existing configurations. The biosensing potential of the developed system, demonstrated through applications to genetic diagnosis and cancer detection, opens the door to a new generation of compact, high-performance, low-cost SPR sensors
Sahour, Mohamed Elhaddi. "Application de la résonance magnétique nucléaire à l'étude des mouvements moléculaires à l'état solide : cas du 1-cyanoadamantane". Lille 1, 1986. http://www.theses.fr/1986LIL10021.
Texto completoLeclerc, Sébastien. "L'inhomogénéité du champ radiofréquence en résonance magnétique nucléaire : expériences et simulations". Nancy 1, 2004. http://docnum.univ-lorraine.fr/public/SCD_T_2004_0038_LECLERC.pdf.
Texto completoThis work deals with the use of radiofrequency field inhomogeneity in nuclear magnetic resonance (NMR). In a first chapter, we present a software for generating and simulating NMR pulse sequences, taking in account the various inhomogeneity types. These simulations were used to design experiments aimed at the determination of CSA-dipolar cross-correlation rate. The second chapter deals with the design of new procedures to select a thin slice of a sample and based on natural radiofrequency field inhomogeneity. We used these procedures, along with a vertical sample displacement, to observe the evolution of the NMR spectrum in a heterogeneous sample. In the third chapter, we present a new method for measuring self-diffusion coefficients based on slice selection procedures. This method was successfully tested on various compounds
Dos, Reis Sánchez Jesús Enrique. "Réseau de capteurs compatible IRM pour l’imagerie cardiaque et la cartographie électrique endocavitaire". Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0107.
Texto completoThe electrocardiogram (ECG) is used to measure heart electrical activity. It has been used during Magnetic Resonance Imaging (MRI) examinations for several decades to improve patient monitoring and synchronize image acquisition. Nevertheless, this technique is performed using electronic devices with a low bandwidth and a limited number of electrodes that do not provide a diagnostic signal quality. Indeed, a diagnostic ECG requires a wide bandwidth (0.05 - 150 Hz) and 10 measuring electrodes that allow 12 leads to be acquired. MRI is characterized by an environment with an intense static magnetic field, high frequency and low frequency dynamic electromagnetic fields. The design and development of an MRI-compatible ECG sensor needs to take into account this environment to reduce the risk of overheating of the device during image sequences and to reduce disturbances on the measured signals. The use of devices with short cables reduces the risk of overheating by antenna effect, which ensures patient safety, but the induction of noise on the signals is inevitable. This thesis is organized in five parts. The first two parts were oriented towards the study of the literature and the design of a new sensor prototype with a broad bandwidth of ECG. The objective was to develop a device with sufficient computing power to integrate the signal processing algorithms developed by the IADI laboratory, to eliminate the noise superimposed on the signals. The third part was dedicated to the construction of a sensor network from N sensors. The goal was to multiply the number of measurement electrodes to increase the spatial resolution of the ECG and reconstruct a 12-lead ECG during MRI examination. The purpose of this work is noninvasive ECG imaging from surface electrical potential maps and from anatomical models of patients obtained simultaneously by MRI. The fourth part presents a new method of real-time correction of ECG signals from a high frequency sampling acquisition, based on the device developed. The fifth and last part presents another application of this sensor in the interventional electrophysiology room, during the activation of a Magnetic Navigation System of the catheter, which generates disturbances similar to those observed in MRI
Andrianoelison, Florent. "Convertisseurs moyenne fréquence à transistor MOSFET en commutation douce : absorption de courants sinusoi͏̈daux sur le réseau de distribution". Toulouse, INPT, 1991. http://www.theses.fr/1991INPT022H.
Texto completoMordret, Aurélien. "Utilisation des correlations de bruit sismique dans un contexte de réseau industriel dense : application au réseau de Valhall". Paris, Institut de physique du globe, 2014. http://www.theses.fr/2014GLOB0301.
Texto completoBeilvert, Anne. "Synthèse, caractérisation et évaluation in vitro et in vivo d'agents de contraste pour l'imagerie moléculaire du coeur lipidique de la plaque d'athérosclérose". Paris 13, 2011. http://www.theses.fr/2011PA132004.
Texto completoImaging and quantifying the lipid core is a key to evaluate the risk of rupture of the atherosclerotic plaque. My goal is to develop MR contrast agent that will target the lipid core inside the atherosclerotic plaque. Our hypothesis is to mimic apolipoprotein A1 and mimetic D-4F behavior with lipids. D-4F is a soluble alpha helix peptide that binds to lipids via a cluster of aromatic amino acids. We believe that using a single aromatic amino acid or a combination of aromatic amino acids on a MR platform will efficiently target the lipid core. First, we developed a micellar platform functionalized with tyrosin-O-methylester. This compound was successfully tested in an ApoE-/- mouse model under western diet that develops atherosclerotic plaque. Then, we generalized this approach with a polysaccharide based MR contrast agent. Tyrosine-O-methylester was coupled to this platform as well as trityrosine and L-4F peptide. These compounds were evaluated first by surface plasmon resonance (SPR) on immobilized lipoproteins and then in the ApoE-/- mouse model. In vivo results indicate an enhancement in the atherosclerotic plaque and in the lipid core that validates our hypothesis
Devauchelle, Anne-Dominique. "Exploration du réseau cérébral impliqué dans les traitements syntaxiques et lexico-sémantiques des phrases". Paris 6, 2008. http://www.theses.fr/2008PA066295.
Texto completoSotta, Paul. "Étude, par résonance magnétique nucléaire du deutérium, de l'ordre orientationnel local dans un réseau polymère sous contrainte uniaxiale". Paris 11, 1987. http://www.theses.fr/1987PA112329.
Texto completoAmorphous polymer networks (elastomers) exhibit both liquid-like and solid-like properties. At a short spatial scale, polymer chains are free to move with respect to each other; on the other hand, the junctions are trapped in a given configuration. This work aims at characterizing the interactions which determine the local behavior of the chains. The approach has been to study how chain segment motions are affected by a uniaxial external constraint. The adopted technique has been the deuterium nuclear magnetic resonance, which gives access to the dynamics and orientational order at the chain segment level. The results as a whole, obtained in poly (dimethylsiloxane) networks (PDMS), reveal the importance of local orientational correlations:- A uniaxial microscopic order is induced by a uniaxial macroscopic constraint ; it has been attributed to orientational correlations between proximate chain segments which give rise to a collective effect in the presence of the external constraint. -Free PDMS chains diffusing in the constrained network exhibit a local orientation which is comparable to that of cross-linked chains; hence, the effect of local correlations may be predominent with respect to the end-to-end stretching of the linked chains. The induced order decreases when the polymer network is diluted with a conventional good solvent ; on the other hand, introducing a few percent free PDMS chains does not perturb the system at a local scale. A description of chain dynamics may thus introduce explicitly the confinement of a chain by its neighbours. A mean field treatment, including both local orientational interactions and the constraints due to cross-link junctions, allows to describe and discuss this collective effect
Morin, Sébastien. "Motions, Order and Consistency: A story Based on the Study of the Dynamics of the Class A beta-Lactamase PSE-4 by NMR". Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27269/27269.pdf.
Texto completoPart I The analysis of spin relaxation data using the model-free formalism is a widely used approach to get insights into protein dynamics on the ps-ns and μs-ms timescales. In order to extract high quality data, multiple magnetic field datasets are required. Combining datasets recorded using different NMR magnets is prone to experimental errors. Hence, the consistency of multiple field spin relaxation data must be carefully verified. Analysis of multiple field spin relaxation data generally proceeds without verification of consistency, i.e. with only the assumption that data is fine. We propose a simple approach to verify the consistency of multiple field relaxation data. Using the proposed tests improves the analytical approach by reducing the presence of artifactual conformational exchange terms. Since these terms are often rationalised in relation with ligand binding or catalysis, improving their confidence yields a better understanding in terms of biology. Part II Class A b-lactamases are involved in antibiotics resistance. They do so by hydrolysing the b-lactam antibiotics. These enzymes have been widely studied by different approaches including mutational studies, MD simulations, X-ray crystallography and NMR. The model enzyme for this class of proteins, TEM-1, has previously been studied by NMR in the laboratory. It was observed that TEM-1 is a highly ordered protein on the ps-ns timescale, with slower μs-ms motions clustered around the active site. In order to characterize further the backbone dynamics of class A b-lactamases, the homologous enzyme PSE-4 was studied by NMR using different approaches such as spin relaxation, CPMG relaxation dispersion, and amide exchange experiments. The same conclusions as for TEM-1 were obtained with a high rigidity along the sequence balanced by slower motions in the vicinity of the active site. These motions might be conserved in class A b-lactamases and potentially be important for catalysis. This hypothesis is further enforced by the backbone resonance assignments for cTEM-17m, a TEM-1/PSE-4 chimera, where many resonances are unobservable around the active site, potentially suffering from line broadening caused by slow motions.
Paquin, Raphaël. "Relaxation de spin nucléaire et dynamique interne dans les biomolécules & imagerie par résonance magnétique en champs inhomogènes". Paris 6, 2010. http://www.theses.fr/2010PA066225.
Texto completoDos, Reis Sánchez Jesús Enrique. "Réseau de capteurs compatible IRM pour l’imagerie cardiaque et la cartographie électrique endocavitaire". Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0107.
Texto completoThe electrocardiogram (ECG) is used to measure heart electrical activity. It has been used during Magnetic Resonance Imaging (MRI) examinations for several decades to improve patient monitoring and synchronize image acquisition. Nevertheless, this technique is performed using electronic devices with a low bandwidth and a limited number of electrodes that do not provide a diagnostic signal quality. Indeed, a diagnostic ECG requires a wide bandwidth (0.05 - 150 Hz) and 10 measuring electrodes that allow 12 leads to be acquired. MRI is characterized by an environment with an intense static magnetic field, high frequency and low frequency dynamic electromagnetic fields. The design and development of an MRI-compatible ECG sensor needs to take into account this environment to reduce the risk of overheating of the device during image sequences and to reduce disturbances on the measured signals. The use of devices with short cables reduces the risk of overheating by antenna effect, which ensures patient safety, but the induction of noise on the signals is inevitable. This thesis is organized in five parts. The first two parts were oriented towards the study of the literature and the design of a new sensor prototype with a broad bandwidth of ECG. The objective was to develop a device with sufficient computing power to integrate the signal processing algorithms developed by the IADI laboratory, to eliminate the noise superimposed on the signals. The third part was dedicated to the construction of a sensor network from N sensors. The goal was to multiply the number of measurement electrodes to increase the spatial resolution of the ECG and reconstruct a 12-lead ECG during MRI examination. The purpose of this work is noninvasive ECG imaging from surface electrical potential maps and from anatomical models of patients obtained simultaneously by MRI. The fourth part presents a new method of real-time correction of ECG signals from a high frequency sampling acquisition, based on the device developed. The fifth and last part presents another application of this sensor in the interventional electrophysiology room, during the activation of a Magnetic Navigation System of the catheter, which generates disturbances similar to those observed in MRI
Pautrat, Alain. "ancrage et dynamique d'un réseau de vortex dans le cadre d'un ancrage de surface". Phd thesis, Université de Caen, 2000. http://tel.archives-ouvertes.fr/tel-00010046.
Texto completoLe, Forner Sylvie. "Modélisation hydrologique des échanges surface-souterrain avec réseau de fossés en milieu agricole méditérranéen". Montpellier 2, 2001. http://www.theses.fr/2001MON20098.
Texto completoMarcou, Olivier. "Modélisation et contrôle d’écoulements à surface libre par la méthode de Boltzmann sur réseau". Perpignan, 2010. http://www.theses.fr/2010PERP1001.
Texto completoThis PhD work considers the general problem of modelling and simulation of complex systems and deals with the domain of control and management of water resources. We propose here an original approach based on Lattice Boltzmann models (LB) for modelling free surface flows in irrigation canals, usually described with the non-linear shallow water equations. We adapted a bi-fluid model and studied the boundary conditions which allow to reproduce the geometry of a free-surface irrigation canal. Methods for estimating the desired hydraulic quantities were developed. We studied the behavior of submerged underflow gates, and we show that the model is able to spontaneously and correctly describe how the gates function in quite different situations. Validations were realized by comparing results from simulations and experimentations performed on a laboratory micro-canal facility. We also introduced sedimentation phenomena in the model and studied the influence of a sedimentation deposit on the flow. Comparisons between experimental and simulation results were also performed and converged
Laplatine, Loïc. "Résolution spatiale en microscopie par résonance de plasmon de surface à couplage par prisme". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY044/document.
Texto completoPrism-based surface plasmon resonance (SPR) microscopy is an optical imaging technique invented in the late 60s'. Its main advantage lies in its high sensitivity to optical index or thickness variations at a metal surface. Therefore, the monitoring of biological reactions can be performed in real-time without labeling agent such as fluorescence or enzymes. Over the last 30 years, SPR microscopy has become the major technique in label-free biodetection. The field of application range from the determination of affinity constant in biochemistry to the detection of pathogenic bacteria via cellular biology. Until now, the propagation length of the surface plasmons has been considered as the spatial resolution limit. However, many examples do not support this statement. In this PhD thesis, we demonstrate that the resolution is also limited by optical aberrations induced by the prism used to couple light and surface plasmons. Thus, we are able to explain why the experimental resolution was usually worse than the predicted one. The analysis of the image formation and the quantification of aberrations lead us to suggest two new optical configurations optimized for resolution. We also analyze which metal exhibits the better trade-off between propagation length and sensitivity. Experimentally, we obtain a resolution between 1.5 and 4 μm depending on the direction, on field-of-view up to several mm2, and with a standard sensitivity for biodetection (monolayer of DNA). We are then able to observe simultaneously several thousands of individual eukaryote and prokaryote cells. Finally, we develop a prototype dedicated to the real-time monitoring of protein secretion by immune cells. The limits of SPR microscopy and the solutions which could allow this kind of study are discussed. Preliminary results on the improvement of bacterial detection are also presented
Pillet, Flavien. "Développement d'un outil d'analyse d'interactions moléculaires basé sur la résonance plasmonique de surface (SPRi)". Thesis, Toulouse, INSA, 2010. http://www.theses.fr/2010ISAT0029/document.
Texto completoDuring the last decades a large number of technologies have been developed to analyze intermolecular interactions. In this context, the fluorescence biochips remain the most frequently used. Although this technology is very sensitive and multiplexed, it does not allow access to the kinetic parameters, essential to the calculation of the constants of affinity. Therefore, the research for alternative systems is essential. In this way, the Surface Plasmon Resonance imaging (SPRi) is considered as an opportunity. It is an optical detection process that can occur when a polarized light hits a prism covered by a thin metal layer. Under certain conditions free electrons at the surface of the biochip absorb incident light photons and convert them into surface plasmon waves. Perturbations at the surface of the biochip, such as an interaction between probes immobilized on the chip and targets, induce a modification of resonance conditions which can be measured. It is a label free technology which allows intermolecular interactions in real time and gives access to the kinetics parameters. However, SPRi is limited in sensitivity and multiplexing. The objectives of my PhD were to circumvent these various limits. Thus, we validated the immobilization of DNA probes on gold surface using thiol-modified oligonucleotide probes. Deposition carried out on non-modified gold surface, does not require electrical stimulation and expensive specific robotic devices. The thiol modification of the probes was shown to be very stable at room temperature, contrary to pyrrole and diazonium probes that need to be prepared just prior to their spotting. We demonstrate that thiol-modified oligonucleotide probes spotted on a gold surface of the SPRi-prisms are very robust and reproducible. We also demonstrated that this simple chemistry is compatible with high density arrays fabrication bearing more than 1000 spots using a classical spotter. Furthermore, the modification of the prism surface with gold colloids and dendrimers allowed for DNA/DNA interactions, to reach a detection limit of 2 nM. In parallel of this work, various biological applications were carried out and validate our previous developments. A first study was to screen G-quadruplex specific ligands to inhibit telomerase activity. We demonstrated that SPRi technology is particularly well adapted to the screening of interaction of small molecules with DNA probes and is sensitive enough to permit distinction between interactions with different DNA structures. The second study was on the bacterial partition complex. We study the DNA binding requirement involved in SopB-sopC specific interactions and analysed at the nucleotide level the bases involved in the binding efficiency and essential for the partition All this PhD work improved the SPRi technology and demonstrated its great potential in biological applications
Le, Nader Victor. "Approche expérimentale et théorique de la diffusion Raman exaltée : résonance des plasmons de surface et effet de pointe". Phd thesis, Université de Nantes, 2010. http://tel.archives-ouvertes.fr/tel-00559365.
Texto completoBéland, Rémy. "Développement d'un biocapteur couplant la résonance des plasmons de surface et la microcalorimétrie pour le suivi des interactions moléculaires à l'interface liquide/solide". Thesis, Ecully, Ecole centrale de Lyon, 2013. http://www.theses.fr/2013ECDL0040/document.
Texto completoTo begin with, the characteristics of a DNA hybridization intermolecular interaction at the interface were defined in order to deduce the specifications for our transducers. Following this, the SPR and microcalorimetric transducer will be design by taking into account the constraints of each one. Following the theoretical design of the sensor, a manufacturing process compatible with standard methods of microelectronics manufacturing was tested and identified. To ensure the functionality of the devices, a test of surface functionalization on the sensor was applied to test the compatibility of the manufacturing process with the surface functionalization methods. Finally, a system of active mixing was tested and characterized with a microcalorimetric device to ensure it was possible to mix fluids with organic products to be sure of the quality of the surface reaction. The system developed can be used to mesure DNA hybridization at the interface. This system incorporates two modalities for real-time characterization of intermolecular interactions near the solid/liquid interface. This type of system allows the kinetic measurement of different biological models such as cellular receptors or it is possible to have some molecular measure conformation near the interface. Oxidation of glucose with the enzyme glucose oxidase was shown to present the possibility to measure a biological interaction
Fuchs, Julia. "Étude physico-chimique des puces à ADN : stabilité du duplex d'ADN, détection des mutations ponctuelles et au-delà". Grenoble 1, 2009. http://www.theses.fr/2009GRE10240.
Texto completoThis Ph. D. Thesis studies phenomena concerning DNA duplex stability. Exploiting a real-time detection system based on Surface Plasmon Resonance imaging (SPRi), we use a temperature scan method to analyze DNA interactions on functionalized biochips. First, a detailed study about a comparison of two DNA immobilization methods and the influence of different buffer components on surface hybridized DNA duplexes is presented. Especially the influence of salt and denaturing agents in the buffer are discussed. Second, we apply the temperature scan method to point mutation detection, as well for oligonucleotides as for longer DNA or RNA targets produced by Polymerase Chain Reaction (PCR) or Nucleic Acid Sequence Based Amplication (NASBA) amplification protocols, respectively. Competition between targets containing point mutations and surface hybridization is addressed. Also, secondary structures in solution may alter target capture on probes. For the isothermal NASBA amplification, we show that it is possible to make an integrated system with amplification and detection on the SPRi chip. Finally, a study of DNA lesions and repair enzymes is presented in collaboration with the 'Laboratory of Nucleic Acids Lesions' (LAN) at the CEA Grenoble profiting once again from the flexible temperature regulation to characterize enzyme activity on surface grafted DNA