Commercial ink-coated PVC: No longer abrading conventional PVC surfaces for electrode fabrication using pencil drawing

Autor(es)

Ferreira, Bruno ; Arantes, Iana V. S. ; Saraiva, Douglas P. M. ; Pradela-Filho, Lauro A. ; Bertotti, Mauro ; Paixao, Thiago R. L. C.

• Tipo de documento: Artigo Científico
• Fonte: Microchemical Journal; v. 198, p. 7-pg., 2024-02-15.

Resumo

Using pencil drawing, a rapid "do-it-yourself" approach is reported to fabricate electrochemical sensors on commercial ink -coated polyvinyl chloride (PVC) substrates. Unlike conventional PVC, the ink -coated substrates have a rougher surface, enabling graphite deposition without a mechanical pretreatment step and simplifying the fabrication method. Three -electrode electrochemical sensors were designed with 2B, 6B, and 8B graphite pencils. Regardless of the pencil type, the fabrication process was conducted with the same number of pencil movements while a commercial multimeter monitored the graphite trails' electrical resistance. 8B graphite pencils exhibited superior performance due to their softness. Such a feature facilitated the graphite exfoliation and deposition, producing continuous conductive trails and enhancing the sensors' electrochemical responses. Similarly to conventional glassy carbon electrodes, the proposed sensors showed a diffusion -controlled electrochemical behavior for the hexaammineruthenium, requiring only 80 mu L of solution for electrochemical measurements. The sensors also exhibited repeatability and reproducibility. Additionally, the sensors' mechanical stability was demonstrated through bending tests, demonstrating robustness. Under optimized conditions, the analytical performance of the sensors was initially evaluated for analytes with forensic and food interest, such as cocainefree base (COC) and caffeic acid (CA). As a proof of concept, caffeic acid was successfully quantified in tea samples using square wave voltammetry, achieving a low detection limit of 0.37 mu mol L-1. Therefore, this work brings a straightforward alternative to fabricating electrochemical sensors using cheap daily -use materials and showcases the resulting device's utility for antioxidant sensing in tea samples. (AU)

• Processo FAPESP: 23/02572-3 - Obtenção de informações químicas em cérebros de rato com um potenciostato portátil
• Beneficiário: Douglas Philip Martinez Saraiva
• Modalidade de apoio: Bolsas no Brasil - Programa Capacitação - Treinamento Técnico
• Processo FAPESP: 21/00205-8 - Dispositivos analíticos miniaturizados e/ou microfluídicos para aplicações biológicas
• Beneficiário: Lauro Antonio Pradela Filho
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/15065-7 - Desenvolvimento de sistemas eletroquímicos em papel voltados para análises em fluxo de amostras de interesse forense
• Beneficiário: Iana Vitória Spadini Arantes
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 18/08782-1 - Sensores químicos miniaturizados e integrados: novas plataformas de fabricação para aplicações biológicas, clínicas e ambientais
• Beneficiário: Mauro Bertotti
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 22/11346-4 - Sistemas microfluídicos impressos em 3D para aplicações analíticas biológicas
• Beneficiário: Lauro Antonio Pradela Filho
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado