Stencil-printed graphene electrodes for affordable electrochemical sensing of capsaicin

Author(s)

Ferreira, Bruno ; Arantes, Iana V. S. ; Gongoni, Juliana L. M. ; Pradela-Filho, Lauro A. ; Paixao, Thiago R. L. C.

• Document type: Journal article
• Source: Microchemical Journal; v. 207, p. 7-pg., 2024-12-01.

Abstract

Disposable electrochemical sensors have gained popularity due to their low cost and manufacturing simplicity. Herein, electrochemical sensors were fabricated on different substrates using commercially available graphene ink. The substrates include watercolor paper (300 g/m2), kraft paper (300 g/m2), office paper (A4), polyvinyl chloride (PVC) and overhead sheets. The fabrication process involved the application of the conductive ink on a geometrically defined mask, generating a three-electrode electrochemical system. PVC plastic substrates provided better electrochemical performance to the devices and ink adhesion on this substrate. Such features were associated with each evaluated substrate's morphologic aspects. The reproducibility of the manufacturing process was evaluated for five PVC devices, resulting in a relative standard deviation (RSD) of 9.2 % for [Ru (NH3)6]3+. Response repeatability was also tested for 10 consecutive measurements, yielding consistent electrochemical response with an RSD of only 2 %. The analytical performance of the resulting sensors was assessed for capsaicin (CAP) quantification, achieving limits of detection (LOD) and quantification (LOQ) of 0.10 and 0.31 mu mol L- 1, respectively. In addition, the proposed sensors showed competitive electrochemical performance compared to previously reported carbon electrodes, highlighting their feasibility for analytical applications with sample microvolumes, as demonstrated through analyses of pepper extract and sauce. Therefore, this work offers a promising alternative to fabricating affordable graphene electrodes for capsaicin electrochemical sensing in real samples. (AU)

• FAPESP's process: 19/15065-7 - Development of paper-based electrochemical systems aiming flow analysis of forensic samples
• Grantee: Iana Vitória Spadini Arantes
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 18/08782-1 - Miniaturized and integrated chemical sensors: new fabrication platforms for biological, clinical and environmental applications
• Grantee: Mauro Bertotti
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 23/00246-1 - Miniaturized large-scale devices for in-situ analysis: fabrication, characterization and applications
• Grantee: Mauro Bertotti
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 21/00205-8 - Miniaturized and/or microfluidic analytical devices for biological applications
• Grantee: Lauro Antonio Pradela Filho
• Support Opportunities: Scholarships in Brazil - Post-Doctoral