Low-cost laser for fabrication of affordable graphene-induced microband sensors

Author(s)

Ribeiro, Leonardo M. A. ; Feria, Deissy. J. ; Falcoswki, Paula C. ; Carreno, Marcelo. N. P. ; Pereyra, Ines ; Bertotti, Mauro

• Document type: Journal article
• Source: Journal of Applied Electrochemistry; v. 54, n. 12, p. 10-pg., 2024-05-16.

Abstract

Graphene microband electrodes were fabricated by direct laser writing on Kapton (R) polyimide tape utilizing a low-cost, blue laser (500 mW and 405 nm). The structural properties of the graphene were examined by Raman spectroscopy, and key features such as D, G, and 2D bands and the presence of multilayer structures were revealed. Scanning electron microscopy (SEM) provided insights into the microband morphology, highlighting the 3D (foam-like) nature of the graphene microbands. Electrochemical experiments revealed cyclic voltammetry profiles that demonstrated radial diffusion dominance at low scan rates and Randles-Sevcik behavior at higher scan rates. Reproducibility and repeatability analyses confirmed the stability and consistency of these microband electrodes within individual devices. Scanning electrochemical microscopy (SECM) images revealed the electrochemical reactivity of the microbands. At a relatively low microband separation (200 mu m), the produced material can be collected at the adjacent microband, which was confirmed via generator/collector experiments. Theoretical-experimental comparisons regarding the current measured for a single microband were performed, and the obtained results were in good agreement, with deviations attributed to the 3D morphology of the microbands. This research underscores the potential of these cost-effective and reproducible graphene microband electrodes for diverse applications in electrochemical sensing, and we present preliminary results on caffeic acid and paracetamol detection. (AU)

• 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: 22/03665-2 - Electrochemical sensors for hydrogen peroxide and calcium ions detection in biological systems
• Grantee: Paula Calli Falcoswki
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)