Interleukin 15 has great application potential such as in the biological treatment of cancer. It is involved in a variety of immunological processes, the most important of these involve influencing and induction of NK cells and T-lymphocytes proliferation. However, its therapeutic usages are limited by a low stability and short half-life. For this reason, there are various approaches of stabilization and expansion of its biological activity being explored. In this work, we analysed and developed a new approach, which uses viral nanostructures derived from major capsid VP1 protein of mouse polyomavirus as a carrier of IL-15. Moreover, VP1 proteins can be relatively easily modified and they are also capable to penetrate into the tumour cells. There were prepared two variants of IL-15 together with control nanostructures in the baculovirus expression system, one was composed of IL-15 and the other of the IL-15 fusion protein and truncated variant of VP1. Protein constructs were characterized by electron microscopy and biochemical methods. The total protein yield of VP1ΔC-IL15-HIS fusion variant was higher (up to 53 mg/L of complete medium) than IL-15 alone (8,5 mg/L). However, testing of the biological activity of the prepared proteins in vitro did not show any induction of proliferation on Jurkat...

Nanostructured materials provide new and exciting approaches to the development of supercapacitor electrodes for high-performance electrochemical energy storage applications. One of the biggest challenges in materials science and engineering, however, is to prepare the nanomaterials with desirable characteristics and to engineer the structures in proper ways. This dissertation presents the successful preparation and application of very promising materials in the area of supercapacitor energy storage, including manganese dioxide and its composites, polyaniline and activated carbons. Attention has been paid to understanding their growth process and performance in supercapacitor devices. The morphological and electrochemical cycling effects, which contribute to the understanding of the energy storage mechanism of MnO2 based supercapacitors is thoroughly investigated. In addition, MnO2 based binary (MnO2-carbon nanocoils, MnO2-graphene) and ternary (MnO2-carbon nanotube-graphene) nanocomposites, as well as two novel electrodes (MnO2-carbon nanotube-textile and MnO2-carbon nanotube-sponge) have been studied as supercapacitor electrode materials, showing much improved electrochemical storage performance with good energy and power densities. Furthermore, a general chemical route was introduced to synthesize different conducting polymers and activated carbons by taking the MnO2 nanostructures as reactive templates. The electrochemical behaviors of the polyaniline and activated nanocarbon supercapacitors demonstrate the morphology-dependent enhancement of capacitance. Excellent energy and power densities were obtained from the template-derived polyaniline and activated carbon based supercapacitors, indicating the success of our proposed chemical route toward the preparation of high performance supercapacitor materials. The work discussed in this dissertation conclusively showed the significance of the preparation of desirable nanomaterials and the design of effective nanostructured electrodes for supercapacitor energy storage applications.

As electronic devices became smaller, interest in quantum-confined semiconductor nanostructures increased. Self-assembled mesoscale semiconductor structures of II-VI nanocrystals are an especially exciting subject because of their controllable band gap and unique photophysical properties. Several preparative methods to synthesize and control the sizes of the individual nanocrystallites and the electronic and optical properties have been intensively studied. Fabrication of patterned nanostructures composed of quantum-confined nanoparticles is the next step toward practical applications. We have developed an innovative method to fabricate diverse nanostructures which relies on the size and a shape of a chosen deoxyribonucleic acid (DNA) template.

Silicon photonics is a powerful technological platform that has advanced with gigantic steps during the past 20 years. Its applications range from the nanoscale, with biosensing and spectroscopy, all the way to the macroscale, with optical fiber communications and on-chip Lidar. However, its commercialization is still hindered by the lack of a cost-effective and automatable chip packaging approaches. At the same time, the current multiplexing techniques to increase the bandwidth density of optical communication networks are hitting their theoretical capacity limits. This has pushed the community to look for additional spatial data transmission paths through a common optical fiber. At the smaller end of the size scale, the controlled self-assembly of nanoparticles is the holy grail of nanotechnologists around the globe. Great advances towards this goal have been demonstrated, but most of the time it is hard to simultaneously control the many variables involved in the self-assembly processes. Silicon photonics and compatible wave guiding techniques are the ideal platform to address these issues thanks to their ability of controlling light in the nanoscale. Regarding the macroscale, this dissertation presents approaches based on micro 3D printing to overcome the silicon photonics packaging bottleneck and to access additional spatial channels to increase the bandwidth density of optical communication channels. Section 2.2 presents the plug-and-play coupling of fibers to waveguides, where a 3D printed optical-mechanical micro connector is defined directly on top of a silicon photonics chip. This connector has such a relaxed alignment tolerance, that even the coarse precision of industrial automated assembly tools is enough to automatically couple a fiber to the waveguide in a robust and passive way. Section 2.3 shows another 3D printed micro coupler design. This coupler optically bridges between the higher order modes of a multimode silicon waveguide and those of a few-mode fiber. These higher order modes can carry different streams of information at the same wavelength, effectively increasing the amount of data transmitted through the same physical channel. Regarding the nanoscale world, there is a very popular but not completely well understood self-assembly technique called evaporative self-assembly. For the past couple of decades scientists have been trying to harness it to deposit controlled patterns of nanostructures (ranging from inorganic nanoparticles to biological elements). The problem with this technique is that several of the physical variables involved in the evaporative self-assembly process are coupled to each other, making it difficult to precisely control the particle deposition. Section 3.3 shows a way of depositing a periodic pattern of gold nanoparticle clusters along the top of a silicon photonics waveguide by assisting the evaporative self-assembly process with optofluidic transport of particles. The particle trapping and transport along a waveguide is possible thanks to the strong optical forces in the immediate vicinity of the waveguide core. With this approach, the evaporative self-assembly deposition pattern periodicity can be controlled simply by tuning only one knob: the input laser power.

Though the past two decades have seen a dramatic increase in research toward self-cleaning repellent surfaces, multiple challenges exist in the creation of biorepellent surfaces for everyday use. Environmental concerns persist with many of the chemicals utilized in this field and the need for scalable, low-cost alternatives remains. Spread of pathogens including bacteria and viruses in healthcare and public settings also presents a need for stable surfaces. In the work presented here, we report on the current status of antimicrobial nanomaterials and coatings toward virus repellency, followed by an investigation into the application of polysiloxane nanostructures in creation of flexible hierarchical surfaces. Using n-propyltrichlorosilane (n-PTCS) coated on activated polyolefin (PO) we were able to demonstrate superhydrophobicity, reporting water contact angles above 153° paired with <1° sliding angles on hierarchical surfaces. A transfer assay, that closely mimics contact with high-touch surfaces, using Escherichia coli K-12 transfected with green fluorescent protein (GFP) reported a 1.6-log (97.5%) reduction in fluorescence on surfaces compared to planar PO controls, paired with a 1.2-log (93%) reduction in CFU/mL in comparison to control groups. Additionally, surfaces demonstrated a contact angle of 140.8° with citrated whole blood. Droplets of blood incubated on our surfaces for 15 min showed a 93% reduction in visible staining, while submersion in citrated whole blood for 20 minutes revealed an 87% reduction in blood adhered to the surfaces. The applications for these biorepellent surfaces have widespread potential, including the demonstrated need for prevention of surface contamination to minimize spread of hospital acquired infections (HAIs) within the healthcare system. / Thesis / Master of Applied Science (MASc) / The goal of creating a surface capable of repelling biological samples continues to present challenges due to surface stability, scalability, and cost of manufacturing techniques. Beyond this, many of the existing solutions use fluorine-based chemicals that present a risk to the environment due to the difficulty in breaking down these molecules. This thesis aims to understand the current state of repellent surfaces used for biological applications, including prevention of surface contamination by bacteria and viruses, then investigates the use of more environmentally friendly methods to produce repellent surfaces. Using a silicone-based coating combined with heat induced shrinking of shape memory polymers (SMPs), we have created a flexible surface with multiscale roughness that demonstrates repellency to bacteria and whole blood.

The peak efficiency range for CdTe solar cells is between 500-700nm; however efficiencies are limited at wavelengths shorter than 500nm due to the fact that at higher energies, most photons are absorbed in the CdS layer of the module and cannot contribute to the cell current. This means that incident photons with higher energies are ‘wasted’ as they are not efficiently absorbed by the cell. Luminescent downshifting (LDS) is a third-generation photovoltaic technology in which an external layer applied to the front surface of the cell absorbs high energy photons and re-emits them towards the cell at energies where they are more efficiently absorbed, thus avoiding front surface loss mechanisms. This research project investigates the use of cerium and terbium co-doped silicon oxide thin films grown using electron cyclotron resonance plasma enhanced chemical vapour deposition (ECR PECVD) as a luminescent down-shifting layer. Post-deposition annealing in a quartz tube furnace caused the formation of cerium disilicate (Ce2Si2O7) nanocrystallites, which were found to strongly absorb incident light at wavelengths below 360 nm and efficiently sensitize Tb3+ ions in the film for re-emission. The effect of annealing time and sample composition on physical and optical properties was studied. Film compositions were determined through Rutherford backscattering spectrometry, revealing an incremental increase in rare earth concentration. Photoluminescence measurements showed a distinct Tb3+ peak around 550nm, which is close to the ideal efficiency wavelength for CdTe photovoltaics. Variable Angle Spectroscopic Ellipsometry measurements were used to determine the index of refraction of as-deposited and annealed films. UV-Visible absorption spectroscopy and transmission ellipsometry measurements showed a sharp increase in absorption around 400nm confirming wide separation between absorption and emission bands. When LDS films were coupled with thin film CdTe, subsequent absorption spectroscopy and transmission measurements showed stronger absorption at short wavelengths, as anticipated. / Thesis / Master of Applied Science (MASc)

Les nanostructures plasmoniques sont à l’origine de nombreuses avancées technologiques aussi bien en recherche analytique ou biomédicale que dans la production et le stockage d’énergie. L’intérêt pour cette nanotechnologie est motivé par l'adaptabilité des propriétés optiques et électroniques réalisable en manipulant la composition et la structure des particules métalliques. Contrairement aux matériaux macroscopiques, un minuscule changement de taille ou de morphologie peut entraîner un important changement dans la réponse optique des particules. Puisque l’efficacité des nanostructures pour le développement d’applications dépend fortement de leurs propriétés plasmoniques, un fin contrôle sur celles-ci est crucial. À cet effet, les nanoparticules creuses présentent un intérêt particulier en raison de la possibilité de moduler leur résonance plasmon de surface localisée (LSPR) par la manipulation du rapport de dimension entre la cavité et la coquille. L’approche la plus directe pour la synthèse de ce type d’architectures est la réaction de remplacement galvanique, dont la première étape est de préparer des nanoparticules de géométrie désirée qui serviront de gabarit sacrificiel, pour ensuite les oxyder avec un métal de potentiel de réduction plus élevé afin de produire une coquille creuse qui suivra la forme du gabarit. Cette approche de synthèse nécessite une maitrise de la cinétique de réaction typiquement obtenue en contrôlant le débit d’incorporation du réactif, par l’ajustement de la température du milieu réactionnel et/ou l’ajout d’un co-réducteur. Cette thèse décrit comment l'efficacité du remplacement galvanique peut être améliorée en contrôlant le degré d'hydratation et d'hydrolyse du précurseur d'ions métalliques (c.-à-d. leur spéciation) en utilisant le pH ou la concentration de ligand comme paramètres de contrôle. Dans ce travail, nous avons démontré que les espèces Au3+ hautement chlorées de forme AuCl4-q(OH)- q remplacent agressivement les nanoparticules Ag et conduisent à des structures brisées alors que les espèces fortement hydrolysées sont inactives en raison de leur potentiel de réduction plus faible à celui de l’argent. Toutefois, en utilisant des ions métalliques partiellement hydrolysés, nous avons pu obtenir des nanostructures creuses avec des parois lisses ou rugueuses. Par ailleurs, les propriétés optiques des nanoparticules creuses Ag-Au telles que les énergies de résonance plasmon et l'intensité des bandes d’extinction et de diffusion ont été analysées. Deux paramètres-clé pour modifier les propriétés optiques ont été étudiées, à savoir, la stœchiométrie atomique des métaux et la taille de la matrice sacrificielle utilisée. Nous avons démontré que la combinaison des deux approches offre de nombreuses possibilités pour le réglage des résonances plasmon. Finalement cette étude a été étendue à d’autres ions métalliques, tels que PdCl2-4- et PtCl2-4- , pour la formation de nanoparticules creuses Ag-Pd et Ag-Pt. / Plasmonic nanostructures are at the origin of many technological advances in analytical or biomedical sciences as well as for the production and storage of energy. The interest for this nanotechnology is motivated by the adaptability of optical and electronic properties achievable by manipulating the composition and structure of the particles. Unlike macroscopic materials, a tiny change in the size or morphology may result in a significant change in the optical response of particles. Since the efficiency of nanostructures for application development strongly depends on their plasmonic properties, a fine control over them is crucial. For this purpose, hollow nanoparticles are of interest because of their highly tunable localized surface plasmon resonance (LSPR) made possible by manipulating the dimension ratio between the cavity and the shell. The most direct approach for synthesizing this type of architecture is the galvanic replacement reaction, where nanoparticles of the desired geometry are first prepared as a sacrificial template and then oxidized with a metal ion of higher reduction potential producing a hollow shell which conforms to the shape of the template. This synthesis approach requires excellent control over reaction kinetics typically obtained by adjusting the rate of incorporation of the reagent, the temperature of the reaction medium, and/or by the addition of a co-reducer. This thesis describes how the efficiency of galvanic replacement can be improved by controlling the degree of hydration and hydrolysis of the metal ion precursor (i.e., the metal ion speciation) using pH or ligand concentration as control parameters. In this work, we have demonstrated that highly chlorinated Au3+ species in the forms of AuCl4-q(OH)- aggressively replace Ag nanoparticles and lead to broken structures while highly hydrolyzed species are inactive due to their lower reduction potential than that of the Ag nanoparticles. However, using partially hydrolyzed metal ions, we were able to obtain hollow nanostructures with smooth or rough walls. In addition, the optical properties of Ag-Au hollow nanoparticles such as the plasmon resonance energies and the intensity of the extinction and diffusion bands were analyzed. Two key parameters to modify the optical properties were studied, namely the atomic stoichiometry of the metals and the size of the sacrificial template. We have shown that the combination of the two approaches offers many possibilities for the tuning of plasmon resonances. Finally, this study was extended to other metal ions, such as PdCl2-4 and PtCl2-4 , for the formation of nanoparticles hollow Ag-Pd and Ag-Pt.

L’objectif principal de ce projet de doctorat porte sur le développement d’architectures nanostructurées afin d’étudier l’interaction par couplage dipôle dipôle entre des molécules chromophores et des particules colloïdales métalliques. Certains métaux nobles comme l’Au ou l’Ag possèdent d’intéressantes propriétés optiques lorsqu’ils se retrouvent sous la forme de nanoparticules. En effet, l’oscillation collective d’électron de conduction, propriété connue sous le nom de plasmon de surface localisé est responsable des couleurs vives et intenses de ces suspensions colloïdales. Ce plasmon de surface entraîne une forte concentration locale du champ électrique qui a été utilisé afin d’amplifier différentes méthodes spectroscopiques comme la fluorescence. L’exaltation de fluorescence par les métaux ou MEF permet d’améliorer les propriétés intrinsèques de fluorophores moléculaires par l’amplification de l’efficacité d’excitation et d’une diminution de leur temps de vie à l’état excité, résultant globalement en une augmentation de l’intensité de fluorescence. Un typed’architecture permettant d’exploiter cette exaltation MEF sont les nanoparticules hybrides coeur-coquille de type metal@silice. Cependant, qu’arrive-t-il lorsqu’on assemble ces nanoparticules en un assemblage plus complexe comme une chaîne de nanoparticules par exemple ? De nouvelles propriétés plasmoniques peuvent alors être exploitées tel le couplage plasmonique entre les nanoparticuleset la propagation d’un plasmon au sein de la chaîne. L’objectif de ce projet est donc d’étudier les propriétés plasmoniques de chaînes de nanoparticules coeur-coquille avec la fluorescence dans le but d’observer une propagation plasmonique. L’assemblage en chaîne de ces nanoparticules hybrides s’est effectué à l’aide d’une technique exploitant une étampe de polydiméthylsiloxane ridée afin d’aligner les nanoparticules à l’intérieur des nanorides formées. L’influence de propriétés géométriques de ces assemblages sur les propriétés de fluorescence d’unfluorophore connu, la fluorescéine, sera présentée. La caractérisation des propriétés optiques de couplages plasmonique par rapport à la taille des coeurs de nanoparticules Ag@SiO2@fluorophore a été réalisé à l’aide de techniques de microscopie de fluorescence, de diffusion en champ sombre et de microscopie de temps de vie de fluorescence. Ces informations fondamentales ont d’ailleurs été appliquées pour étudier la propagation plasmonique dans ces assemblages linéaires de nanoparticules hybrides à l’aide d’une nouvelle technique d’imagerie de fluorescence et plasmon par onde évanescente de guides d’onde photo-inscrits.De plus, une nouvelle technique d’excitation par onde évanescente de guides d’onde photo-inscrits sera présentée pour l’imagerie de propagation plasmonique. La fabrication de ces guides, par photoinscription dans des substrats de silice est réalisée en collaboration avec le groupe du Prof. Réal Vallée du Centre d’Optique, Photonique et Laser à l’aide d’un laser à impulsion femtoseconde. Le positionnement des guides d’onde près de la surface du substrat créer une méthode d’excitation en champ proche par l’onde évanescente éliminant ainsi les problèmes de signaux parasites provenant du volume avoisinant la surface.

No description available.

No description available.