Banca de DEFESA: BRUNA GOMES MACIEL
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : BRUNA GOMES MACIEL
DATE: 07/11/2022
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:
APPLICATION OF NANOCTRUCTURES FOR ENVIRONMENTAL REMEDIATION, DNA EXTRACTION, SUPERCAPACITOR AND NUCLEIC ACID DETECTION
KEY WORDS:
Magnetic nanocomposite. Dye removal. DNA extraction. supercapacitor. Gold nanoparticles. Nucleic acid detection.
PAGES: 106
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:
In this work, we approach the preparation and characterization of nanostructured materials and their application in different areas, such as contaminant removal, DNA extraction and purification, supercapacitor, and sensing of the Leishmania pathogen. Initially, we synthesized the magnetic nanocomposite (MNC) of iron oxide/chitosan/polyaniline (γ-Fe2O3/Chi/Pani), which was properly characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), magnetization curves and X-ray diffraction (XRD). This nanocomposite was then applied to remove dyes (methyl orange (AM), indigo carmine (IC) and rhodamine B (RB)) dispersed in an aqueous medium. For this, we analyzed the effect of variations in parameters such as the pH value of the medium, the dye concentration and the interaction time, which allowed us to adjust the data to different models used in the description of the isotherms and the kinetics of the process of adsorption of contaminants. When using 2 mg of MNC, the adsorption capacity was 147 mg for AM, 126 mg for IC, and 80 mg for rhodamine, values considered promising compared to the performance of other adsorbent materials described in the literature. We also examined the influence of temperature variation on adsorption, which allowed us to establish that the process occurs spontaneously and is endothermic in nature. This same nanocomposite was also used to extract DNA from samples of a complex nature, such as human blood. In this step, different parameters were optimized, such as the amount of MNC to be used, the volume of adequate buffer solution to promote desorption, and the results obtained were then compared with those resulting from the use of commercial kits based on column systems (membranes) and particles. Still during the doctorate, we started two additional lines of work in parallel. The first concerns electrodes for energy storage devices based on eggshell membranes (MCO) that were demineralized and subjected to an ultrasonic tip with the subsequent incorporation of carbon nanostructures (NEC) as multilayer carbon nanotubes (MWCNT), and then the addition of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS). Here, our objective was to improve the electrical conduction and energy storage properties by the phenomenon of electrical double layer (EDC) and pseudocapacitance (PsC), in energy storage devices such as organic supercapacitors. The second project was aimed at the development of a platform formed by a functionalized glass substrate and gold nanoparticles (NPs) that can be used for diagnostic tests. For this, we implemented functionalization studies of glass substrates by the vapor-phase deposition of thiolated and amine groups, which were then placed to interact with gold NPs to form nanostructured films. Through spectroscopy in the ultraviolet and visible region (UV-Vis) and scanning electron microscopy (SEM-STEM) it was possible to follow the steps. Next, we performed proofs of concepts for the detection of nucleic acid through the immobilization of thiolated probes of DNA from the Leishmania infantum pathogen, which demonstrates the potential of this research.
COMMITTEE MEMBERS:
Externa à Instituição - CLARISSA DE ALMEIDA OLIVATI - UNESP
Externa à Instituição - MARYSTELA FERREIRA - UFSCAR
Presidente - 1130294 - CELSO PINTO DE MELO
Interno - 1354207 - SEVERINO ALVES JUNIOR
Interna - 1283002 - YEDA MEDEIROS BASTOS DE ALMEIDA