Magnetic nanoparticles for biosensing and immunoprecipitation

• Autor(a) principal: Beltran, Christian Hazael Perez
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/13939
• topic: Magnetic nanoparticles (MNPs); Environmental control; Biosensor; Irreversible inhibition; Biomedicine; Immunoprecipitation; Sonocatalysis; Green analytical chemistry; Design of experiments; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Our world is rapidly changing and its future is on our hands. Great effort is being done against overexploitation of natural resources, uncontrolled hunting and pollution. A great concerning fact is due to pollution which is causing a continuous greenhouse effect and new cancer cases every single day. Nowadays, it is possible to improve the detection of lethal elements in the environment, to fight against cancer in a smarter manner, with less pain and with more efficiency but, more important, to use the same low-cost, fast and environmentally friendly tool for these purposes and more. This reality is thanks to previous works and findings regarding the Magnetic Nanoparticles (MNPs), which are employable in a wide variety of applications such as magnetic recording media, resonance imaging, heavy metals ions removal and biomedicine (specifically in the hyperthermic treatment of malignant cells, site-specific drug delivery and separation of proteins and cell population). MNPs have special properties such as superparamagnetic, high field irreversibility, high saturation field, extra anisotropy contributions or shifted loops after field cooling, biocompatibility, long durability, low toxicity and cost. In this context, this project intends 1) to develop through a novel synthesis method, a biosensor capable to detect mercury in water by irreversible inhibition of the enzyme Horseradish Peroxidase attached onto the surface of different coated MNPs being able to approximate its detections to those limits stablished by the Environmental Protecting Agency of the United States of America; and 2) to use these high valuable nanoparticles as an immunoprecipitation vehicle through the attachment of a polyclonal antibody onto the surface of functionalized MNPs, selective against a suppressor protein. MNPs of about 10 nm were obtained within one minute via co-precipitation method enhanced by high power ultrasound. Experimental design has been used in order to optimize the preparation process from hours to just one minute. The composition, structure, size and morphology analyses of these MNPs have been carried out through X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy showing the correct achievement of the MNPs. Moreover, different coating agents have been tested in order to functionalize MNPs surface with the aim of attaching later biomolecules, such as enzymes and antibodies.