Banca de QUALIFICAÇÃO: ARTHUR LUIS SILVA DE ARAUJO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ARTHUR LUIS SILVA DE ARAUJO
DATE: 25/04/2025
TIME: 14:00
LOCAL: Auditório do Departamento de Química
TITLE:

MULTIFUNCTIONAL LUMINESCENT MATERIALS AS POTENTIAL TOOLS FOR INCREASING AGRICULTURAL PRODUCTIVITY IN THE STATE OF PERNAMBUCO

KEY WORDS:

Alternative fertilizers; chemical doping; photosynthesis stimulation; plant nutrition; entomology; biocompatible nanomaterials.

PAGES: 110
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:

Brazil is one of the world's leading agricultural producers, but in 2025, it will still depend on foreign fertilizers and pesticides. For this reason, new alternatives to fertilizers and agricultural pesticides have been sought. In this context, carbon dots (CDs) have been gaining greater visibility in improving agricultural production. So far, only studies on plant development have been carried out. Still, no research has sought to analyze the metabolic effect of CDs on plants and their biological interactions with soil microorganisms and herbivorous predators. Therefore, this work aims to synthesize nitrogen, boron, and silicon-doped CDs (BNSi-CDs) and evaluate their effects on the red pitanga crop (Eugenia uniflora). Parameters such as (1) plant growth (number of leaves, leaf area, root size); (2) quantification of volatile compounds and correlation with metabolic pathways of the plant; (3) evaluation of the induced effect on the photosynthetic process, on the strengthening of the plant cell wall and plant nutrition level; and (4) to investigate the potential insecticidal/repellent power of BNSi-CDs against the pests Eugeniamyia dispar, Plutella xylostella, and Tetranychus urticae. BNSi-PC was characterized by luminescence, electronic absorption, vibrational, and energy dispersive spectroscopy (EDS). The morphology of the nanoparticles was analyzed by scanning electron microscopy. The volatile profile and composition of the essential oil were performed in a gas chromatograph coupled with mass spectrometry. Plant health was verified by electrolyte leak test, and spectrophotometric methods determined the C, N, B, and P content. The chemical composition the soil was determined by ICP-OES, and the basal respiration index calculated the richness of the terrestrial microbiota. The formation of BNSi-CDs was evidenced by the characteristic signs of the aforementioned techniques, especially in EDS. The headspace method confirmed the presence of several essential semiochemicals and an increase of >250% in the curzerene content. The effect of the nanoparticles on the activation and deactivation of biological pathways of synthesis of substances associated with communication with pollinating agents was also observed. The biometric results caused by applying BNSi-CDs indicated an increase in all the parameters evaluated. Furthermore, qualitative aspects indicated a strengthening of the plant tissue, resistance to predation by E. dispar, and improved nutrient uptake (greater root volume).

COMMITTEE MEMBERS:
Externo ao Programa - 1188944 - FERNANDO JOSE FREIRE - nullExterno ao Programa - 3091058 - JEAN CHEYSON BARROS DOS SANTOS - nullInterna - ***.999.014-** - JULIANA ANGEIRAS BATISTA DA SILVA - UFPE
Presidente - WAGNER EDUARDO DA SILVA