Development of portable electrochemical devices on polymer materials using CO2 laser for analytical applications

• Autor(a) principal: Mendes, Letícia Francine
• Data de Publicação: 2023
• Tipo de documento: Tese
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://www.teses.usp.br/teses/disponiveis/46/46136/tde-11122023-154239/
• topic: Dispositivos portáteis; Electrochemical sensor; Laser-scribing technique; Lowcost material; Material de baixo custo; Plataformas poliméricas; Polymeric platforms; Portable devices; Sensor eletroquímico; Sensores vestíveis; Técnica de gravação a laser; Wearable sensors

This work is divided into two parts. First, I studied the use of two different nonconductive polymeric platforms to develop portable electrochemical devices using the laser-scribing technique as a scalable, low-cost, easy method to fabricate portable devices. Phenolic paper, a low-cost, rigid board that can easily be bought or recycled from used systems, as another alternative material for fabricating laser-scribed electrochemical divices, provided a conductive carbon-based material containing a porous structure with graphene-like domains. Furthermore, an electrochemical treatment on the fabricated material provided excellent conductivity and low chargetransfer resistance. Thus, great potential for on-site analytical applications was observed when using these devices, achieving better performances than conventional carbon electrodes. Polyimide is another polymeric material widely used to obtain electrochemical devices using laser-scribing. In this work, a low-cost polyimide source, Kapton tape, was also used to fabricate a flexible device. This device was applied using static conditions and a paper-based platform to obtain a microfluid system using hydrodynamic conditions. A low-cost, flexible, and versatile electrochemical platform was obtained, where the analytical performance of the system was evaluated in both static and hydrodynamic modes, presenting great potential for analytical applications when compared to conventional platforms. In the second part of this work, an initial study with microneedles to learn about wearable sensors was carried out in my research internship abroad. A hollow microneedle arraybased electrochemical sensor was studied, aiming at minimally invasive monitoring of propofol drug. Although more studies are necessary, the new microneedle array sensing platform holds excellent potential for continuously monitoring the anesthetic propofol drug during surgical procedures.