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)

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This thesis presents the fabrication of Sn-doped In2O3 nanostructures on a 50 nm thick SiN membrane and their characterization using monochromated electron energy loss spectroscopy (EELS). Rapidly annealed triangular structures of varying thicknesses (71 nm and 32 nm) and lengths (between 400 nm and 1200 nm) unveil a structural crystallization, as well as a blue-shift and narrowing of surface (first and second order modes) and bulk plasmon peaks as the free carrier concentration increases. Bulk peak positions shift from 515+/-39 meV to 628+/-36 meV for 71 nm thick triangles. The second order surface plasmon modes exhibit a greater blue-shift after annealing (93 meV) than the first order modes (36 meV), consistent with the trend found in boundary element method (BEM) simulations using ellipsometry data. The Richardson-Lucy (RL) deconvolution algorithm is employed to improve the effective energy resolution and reveal these surface plasmons as well as a substrate phonon at 100+/-19 meV. Low-loss EELS spectra for 32 nm thick triangles potentially show a blue-shifting bulk plasmon from 751+/-42 meV to 912+/-42 meV with decreasing triangle size. STEM imaging of the triangle structure cross-sections may show a clustering of oxygen vacancies and indium atoms that could be responsible for this blue-shift. Core-loss EELS spectra between 380-550 eV using the oxygen K-edge signal provide evidence of a change in the bonding across the ITO/SiN interface, although its effect on the electrical properties requires further investigation. / Thesis / Master of Applied Science (MASc) / The push towards smaller, faster electronic devices and sensing equipment has accelerated research into manipulating oscillating groups of electrons, or plasmons. So far, the building blocks of these next-generation systems use metals such as gold and silver; however, new materials must be explored for them to be commercially viable. Thin continuous films of transparent conductive oxides (TCOs) such as Sn-doped Indium Oxide (ITO) are already widely used in conventional silicon-based technologies, and in this work ITO nanostructures are fabricated to visualize their plasmonic response, in the hopes that they could be tailored towards plasmonic devices. The relationships between how these plasmons evolve with varying dimensions and the application of heat are explored using electron microscopy.

No / To fully harness the enormous potential offered by interfaces between graphitic nanostructures and biomolecules, detailed connections between adsorbed conformations and adsorption behaviour are needed. To elucidate these links, a key approach, in partnership with experimental techniques, is molecular simulation. For this, a force-field (FF) that can appropriately capture the relevant physics and chemistry of these complex bio-interfaces, while allowing extensive conformational sampling, and also supporting inter-operability with known biological FFs, is a pivotal requirement. Here, we present and apply such a force-field, GRAPPA, designed to work with the CHARMM FF. GRAPPA is an efficiently implemented polarisable force-field, informed by extensive plane-wave DFT calculations using the revPBE-vdW-DF functional. GRAPPA adequately recovers the spatial and orientational structuring of the aqueous interface of graphene and carbon nanotubes, compared with more sophisticated approaches. We apply GRAPPA to determine the free energy of adsorption for a range of amino acids, identifying Trp, Tyr and Arg to have the strongest binding affinity and Asp to be a weak binder. The GRAPPA FF can be readily incorporated into mainstream simulation packages, and will enable large-scale polarisable biointerfacial simulations at graphitic interfaces, that will aid the development of biomolecule-mediated, solution-based graphene processing and self-assembly strategies. / Veski