Nanocomposites as probes for biodetection by SERS

The present work aimed to explore the potential of new nanocomposites based on carbon nanostructures and metal nanoparticles for the detection of biomolecules through surface enhanced Raman scattering (SERS). In a first step, polyvinyl alcohol composites were prepared incorporating silver nanoparticles by two different reduction procedures. At first without introduction of carbon nanostructures. These composites showed good results for the SERS identification of nucleic acids. Next, the synthesis and characterization of graphene oxide was studied to be used in the preparation of silver and gold nanocomposites. The reduction of this nanomaterial with different chemical agents was explored, since its reduction degree may be a determinant factor for the application envisaged (biomolecules interaction). The preparation of the nanocomposites with silver and gold was performed with different reducing agents. The SERS activity of these new nanocomposites was then explored in the presence of different analytes, varying the experimental conditions for Raman spectra acquisition. It was interesting to verify that the silver containing nanocomposites presented the particularity to intensify the graphene D and G bands. It is also important to highlight that a new eco-friendly reducing agent was tested for the synthesis of the graphene oxide composites, an Eucalyptus Globulus extract. Other variable introduced was the preparation of gold nanostars synthesized with hydroxylamine in the presence of graphene oxide, which allowed the preparation of a new nanocomposite with SERS potential. Fibrous membranes were also prepared by electrospinning with the aim to prepare SERS supports with adequate topography and porosity for the formation of nanoparticles agglomerates for the creation of the so-called hot-spots and also to allow the penetration of the analyte molecules. The polymers polyvinyl alcohol and polyacrylonitrile were selected for electrospinning. Using this technique, electrospun mantles with silver and gold nanoparticles and nanocomposites were prepared. Several variables were studied, such as the introduction of the nano-fillers during the electrospinning process, later deposition of the nano-fillers on the simple electrospun polymeric fibres and surface functionalization of the simple polymeric membranes to link the nano-fillers. At last, the potentialities of using carbon nanotubes forests, produced by chemical vapor deposition and coated with gold film by sputtering, as new SERS substrates were explored. It was found that the SERS detection of DNA bases and ADN itself is possible using these substrates.

Exposições museológicas: a moda por narrativas, experiências e conexões

Este estudo apresenta o universo patrimonial pela perspetiva da acessibilidade pública conferida por instituições museológicas. Consiste em exploração e análise das informações e experiências proporcionadas por museus no âmbito da cultura material indumentária e de moda. O foco desta abordagem são as exposições presenciais e os websites institucionais, com ênfase à acessibilidade aos catálogos de coleções. Pela perspectiva do designer como antropólogo neste estudo – com base em estudos de caso e outros dados coletados – são apresentadas ferramentas comparativas da realidade atual e propostas para a disseminação mais alargada, diversificada e especializada das informações cultura material e imaterial de moda. Duas hipóteses orientaram esta tese: - A noção de que as exposições de artefatos de traje podem ser inovadoras em relação às exposições de outros objetos, já que a roupa vincula-se a movimento, toque, corpo e usabilidade que induz experiências e conexões, sentimentos e identidades em uma relação de metamorfose. - A noção de que o potencial de ensino e difusão de uma cultura de design, com destaque aos contextos de Portugal e Brasil, é um campo relevante à visibilidade pública da indústria da moda nestes países e alavanca para um melhor posicionamento na competitividade global. Pelas propostas específicas e pelo contributo de fornecer informações inéditas a respeito do universo investigado, este estudo abre novas perspectivas para futuras investigações, principalmente nas áreas de museologia, museografia, história e teoria da moda e do design, design de exposição, design de produto, estudos da cultura material, comunicação e antropologia do design.