Banca de DEFESA: RAPHAEL DE MEDEIROS SOUTO MAIOR BALTAR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAPHAEL DE MEDEIROS SOUTO MAIOR BALTAR
DATE: 20/12/2023
TIME: 08:30
LOCAL: Sessão por videoconferência.
TITLE:

OPTIMIZATION STRATEGIES FOR COLORIMETRIC PLASMNIC SENSING SYSTEM: EXPLORING METALLIC NANOSHELLS AND CHROMATIC ADAPTATION.

KEY WORDS:

Colorimetry; Nanoparticles, Optical Sensor.

PAGES: 121
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUMMARY:

Colorimetric sensors that operate based on localized surface plasmon resonance have gained prominence in both academia and industry, being applied in several areas, including medicine, biology and chemistry. The use of colorimetric sensors is limited to the development of high sensitivity sensor platforms, the inherent dependence on the lighting sources and the reading system used, which guarantee the robustness of the sensing. The present Doctoral thesis aimed to evaluate the use of chromatic adaptation and metallic nanoshells (SiO2 core and silver and gold shells) for the establishment of a colorimetric sensing system. Here we consider the sensing system composed of a nanosensor platform (nanoshells) and a colorimetric reading system. A procedure for optimizing the colorimetric sensitivity of the nanosensor platform was established considering the influence of the geometric properties of the nanoshells, different lighting sources and the use of different color spaces. Mie theory was explored in the analysis of the spectral response of nanoparticles. The designed colorimetric reading system used a self-referenced image processing procedure, based on chromatic adaptation. The implementation of chromatic adaptation techniques was used as a strategy to improve the robustness of colorimetric measurements in different lighting conditions. The sensor platforms with the highest colorimetric sensitivity and that met the established linearity criterion were identified. The gold nanoshell with a radius of 10 nm and a shell thickness of 5 nm showed greater colorimetric sensitivity (4.7 ) for the Hue color component (HSV color space) and the silver nanoshell with a radius of 20 nm and shell thickness 5 nm shell achieved maximum colorimetric sensitivity (5.57 ) for the Saturation color component (IHSV color space). The “XYZ Scaling” chromatic adaptation technique reduced the average color distance by up to 96% between images from the sensor platform under different illuminants. The results represent a significant contribution to increasing the sensitivity of plasmonic nanosensors and the reliability of colorimetric measurements in the face of variations inherent to lighting sources.

COMMITTEE MEMBERS:
Externo ao Programa - 1295016 - ANDERSON MONTEIRO AMARAL - nullExterno ao Programa - 1760478 - EMERY CLEITON CABRAL CORREIA LINS - nullExterno ao Programa - 1055817 - JOAO MARCELO XAVIER NATARIO TEIXEIRA - nullInterno - 2226204 - JOAQUIM FERREIRA MARTINS FILHO
Presidente - 2199776 - RENATO EVANGELISTA DE ARAUJO