Sensing of biorelevant molecules with metal-organic framework films

• Autor(a) principal: Reis, Ana Rita
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/148365
• topic: Cyclic voltammetry; cathodic deposition; films; uric acid; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química

Uric acid plays a major role in medical applications since its abnormal concentration translates into a diagnostic tool for clinical disorders such as gout, hyperuricemia or the Lesch–Nyhan syndrome. Therefore, the development of purine sensors became significant and relies on the fabrication of thin films and/or membranes based on nanomaterials. Metal-organic frame-works are constituted by organic linkers and metal ions. These have shown some promising results as sensors that can be attributed to their crystallinity, high and permanent porosity, and the presence of several active sites. This work will focus on Fe-MOF-74, with a crystal structure consisting of hexagonal channels and highly reactive metal sites. Metal-organic frameworks are conventionally prepared by solvothermal/hydrothermal methods, obtained as microcrystalline powders. These indirect techniques become limited by the complexity in casting the material to the desired shape. Direct techniques have been used to overcome these limitations, namely, the electrochemical method. This work reports the cathodic deposition of Fe-MOF-74 for the electrochemical detection of uric acid. Herein, pro-ligands were synthesised and characterised by nuclear magnetic resonance, Fourier transform infrared spectroscopy and elemental analysis. The electro-synthesised films were characterised by Fourier transform infrared spectroscopy, elemental analysis, atomic force microscopy, X-ray diffraction, Brunauer, Emmett and Teller surface area from N2 adsorption, scanning electron microscopy, particle-induced X-ray emission and Rutherford backscatter spectrometry. Finally, these films were applied to the electrochemical detection of uric acid and evaluated based on their limit of detection, sensitivity, and linear range.