Banca de DEFESA: JULIA DELATORRE BRONZATO ZAZYKI

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JULIA DELATORRE BRONZATO ZAZYKI
DATE: 28/02/2023
TIME: 14:00
LOCAL: Online
TITLE:

Synthesis and Interaction of Metal Oxide Nanostructures with Biomolecules

PAGES: 86
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Cobalt oxide (Co3O4) is a material with a diversity of applications, and the desirable properties are enhanced in the nanocrystalline structure. Several techniques have been developed for the synthesis of Co3O4. Some routes make use of biomolecules as co-adjuvants by using purified proteins, such as ferritin, and plant extracts. In the present study, cobalt (II) nitrate hexahydrate was used for the synthesis of cobalt oxide nanoparticles and quantum dots in tomato extract under stirring and horse ferritin. Ferritin is present in animal and vegetable species and is a source for green, cheap and facile synthesis of cobalt oxide with important technological applications. Ferritin is an iron storage protein composed of 24 α-helix rich polypeptide chains that is also used by living organisms to produce magnetic materials. Apoferritin has specific sites with binding affinity to metals such as gold and cobalt. Quantum dots of Co3O4 were fabricated using cobalt II nitrate hexahydrate with tomato (Solanum Lycopersicum L.) seed extract, at room temperature. The QDs were characterized by UV-visible spectrophotometry, high-resolution transmission electron microscopy (HRTEM), X-ray excited photoelectron spectrometer (XPS), Fourier transform infrared spectrometer (FTIR), and superconducting quantum interference device (SQUID). Co3O4 QDs present chirality evidenced by magnetic circular dichroism. Consistent with previous Mössbauer data, electron paramagnetic resonance (EPR) revealed the presence of the iron ferritin as the dominant iron ion signal in tomato seeds. Horse spleen ferritin was equally efficient to produce Co3O4 QDs. 

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