Banca de QUALIFICAÇÃO: FRANCISCO CÉSAR COSTA LINS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : FRANCISCO CÉSAR COSTA LINS
DATE: 08/02/2024
TIME: 14:00
LOCAL: Auditório do Departamento de Química
TITLE:

COMPOSITES CONTAINING CdSe quantum dots AS FLUORESCENT NANOPLATFORMS FOR DETECTING HUMAN BODY FLUIDS FOR APPLICATION IN FORENSIC SCIENCES

KEY WORDS:

CdSe quantum dots; Latent fingerprints; Immobilization in silica;

PAGES: 80
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:

This work aims to explore the use of CdSe quantum dots (QDs) associated to silica and silicate materials as fluorescent nanoplatforms in the detection of human bodily fluids, with an emphasis on applications in forensic sciences, specifically in the detection of latent fingerprints (IDLs). The QDs synthesis methodology was based on the bottom-up method carried out in a single reactor (one pot) in a hydrophobic colloidal medium. Electronic absorption and emission analyzes in the UV-visible region demonstrated the success in obtaining QDs with dimensions below 4 nm with orange emission. The immobilization of QDs in silica matrix was carried out through direct contact of the matrix, in a liquid medium, followed by filtration, washing and drying of the material. The dry systems were characterized using emission spectroscopy, Scanning and Transmission Electron Microscopy. To test hybrid materials in IDLs, different forms of impregnation of the materials were carried out in both liquid and powder form. The first results indicate that the CdSe QDs were able to be impregnated in silica-based materials, with hydrophobic silica (CdSe/SiO2) and sodium silicate (CdSe/Na2SiO3) immobilization showing better efficiency (fluorescence permanence) being reflected in the emission spectra, which showed changes in the band's properties, as an indication of association with the matrix. Analysis of the pairs of IDLs impregnated with fluorescent materials demonstrated that there is interaction with specific regions, but that the impregnation process and materials still need to be optimized.

COMMITTEE MEMBERS:
Externa à Instituição - MARIA ISABELA DE ANDRADE PEREIRA
Externo à Instituição - ANTONIO GOMES DE CASTRO NETO - UFPE
Presidente - ***.823.784-** - BEATE SAEGESSER SANTOS - UFPE
Interna - MONICA FREIRE BELIAN