Abstract
Optical fibers are cylindrical waveguides, usually made of silica or acrylic, and with many potential applications in chemical and biochemical sensing, including detection of gases and vapours, medical analysis, molecular biotechnology, environmental and industrial analysis, bioprocesses control, and even for the monitoring of cellular reproduction. In this project, the fabrication of non-conventional optical fibers for chemical sensing is proposed, highlighting the techniques for fabricating hydrogel-based waveguides and microstructured fibers with hydrogels immobilized inside their cavities. Hydrogels are made up of networks of hydrofilic cross-linked polymers, contain until about 30% of water in their total mass, and show many applications, such as controlled drug release and fabrication of ocullar devices. The production of waveguides from hydrogels allows, then,to obtain biocompatible, biodegradable and low-cost photonic devices, which can occlude fluorescent structures in their matrices, like inorganic quantum dots. These particles, on the other hand, present high costs and toxicity, so a viable alternative for sensing is the use of biocompatible fluorescent carbon nanoparticles, obtained from low-cost sources an by microwave-assisted synthesis, the Carbon nanodots, which can be chemically functionalized for the modification of the light emission patttern when in the presence of substances of interest. The project will focus on the development based on agarose, alginate and gelatin, but other materials and other special fibers fabrication approaches may be tested for comparison, in case of verifying their viability. (AU)
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