Banca de QUALIFICAÇÃO: LUCAS COSTA FAUSTINO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE: LUCAS COSTA FAUSTINO
DATA: 05/10/2022
HORA: 08:30
LOCAL: Auditório do PPGQ-UFPI (Virtual)
TÍTULO: 3D-printed pencil holder: toward improving reproducibility of hand-drawing graphite electrodes on paper for point-of-care analysis
PALAVRAS-CHAVES: 3D printing; pencil drawn; electrochemical sensors; graphite; portable devices
PÁGINAS: 20
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Físico-Química
ESPECIALIDADE: Eletroquímica
RESUMO:

Currently, electrochemistry has concentrated numerous studies aimed at developing simple and cost-effective analytical tools for several applications, ranging from environmental monitoring to clinical diagnostics. Part of this dedication focuses on development of paper-based and other platforms and devices for on-site analysis, which has received incredible attention lately. In 2013, Dossi and co-workers introduced a simple approach for preparing miniaturized electrodes in paper-substrates by hand-drawing of graphite using pencil leads, resulting in affordable electrochemical microfluidic paper-based analytical devices (E-µPAD), which was lately employed for several applications by his group and other researchers that started to use his approach. Despite the advantages of the strategy proposed by Dossi, such as low cost and easy manufacturing, it wasn’t easy to be reproduced by other research groups or even in the same group, especially due to the angulation of the pencil lead during manufacturing and pressure used for the electrodes drawing. Although using plotters/cutters coupled to pencil leads make it possible to draw the electrodes in a controlled manner, this would increase the cost of production and the accessibility of such technology, since they are expensive pieces of equipment and not accessible in remote locations or with limited investment. With the advent of additive manufacturing technology or better known as 3D printing, several advantages have emerged in the development of portable devices, such as rapid prototyping, reduction in waste of materials and the use of cheap and biodegradable materials. Therefore, in this work, a 3D-printed holder (3DPH) for manual confection of these miniaturized pencil-based graphite electrodes in paper platform was developed to ensure 90° angulation of pencil lead and same pressure during deposition independent on the operator, thus improving reproducibility and reducing costs for confection of these devices. In addition, it is also presented an optimized 3D electrochemical cell for simple and agile application of pencil-drawn electrodes. Results shown great reproducibility and precision of the 3DPH-assisted electrodes prepared by 4 different operators in terms of sheet resistance and electrochemical behavior, when compared to the electrodes prepared without the 3D printed holder. Besides, MEV images demonstrated that the electrodes drawing/deposition were more uniform and with well-defined width when prepared by using 3DPH, which corroborated to their reproducibility. As proof of concept, 3DPH-assisted pencil-drawn graphite electrodes were employed for the detection of dopamine. Finally, we believe that this approach can make pencil-drawn technology more accurate, reproducible, robust, and also accessible and inexpensive for on-site applications, especially in places of difficult access or research centers with little investment.

MEMBROS DA BANCA:
Presidente - 1998602 - EVERSON THIAGO SANTOS GERONCIO DA SILVA
Interno - 2406262 - ROBERTO ALVES DE SOUSA LUZ
Interno - 1508806 - WELTER CANTANHEDE DA SILVA
Externo à Instituição - WENDELL KARLOS TOMAZELLI COLTRO - UFG