Laser-treated thermoplastic carbon electrodes for enhanced performance of electrochemical sensors

Description:
Thermoplastic electrodes (TPEs) are based on a mixture of carbonaceous materials (graphite, carbon black, graphene, etc.) with thermopolymer binders1–3. They represent a carbon electrode alternative due to their tunable mechanical and electrochemical properties. In addition, TPEs can be patterned into many complex geometries, providing flexibility depending on the desired application. The electrochemical performance of TPEs relies on the type of treatment given to their surface, including sanding, polishing, and plasma treatment4. Herein, we present the use of a CO2 laser for surface activation of TPEs for the first time. An array of TPEs was used containing 4 sets of electrodes, each containing a counter, reference, and working electrodes. The electrodes were fabricated by mixing graphite in a blend of polycaprolactone (PCL) and polystyrene (PS).CO2 laser parameters such as laser power and scan rate were optimized, and these values were 8 and 30%, respectively. The total duration of the treatment was 18 seconds. The electrochemical response of different redox probes, such as ferri/ferrocyanide, ascorbic acid, and dopamine, were evaluated. After activating the surface of the TPEs using a CO2 laser, there was a significant improvement in their electrochemical performance. The electrodes were further characterized by SEM, XPS, optical profilometer, and EIS.

1 McCord, C. P.; Summers, B.; Henry, C. S. Redox Behavior and Surface Morphology of Polystyrene Thermoplastic Electrodes. Electrochim. Acta 2021
2 Clark, K. M.; Henry, C. S. Thermoplastic Electrode ( TPE ) -Based Enzymatic Glucose Sensor Using Polycaprolactone-Graphite Composites Research Article. 2021
3 Ozer, T.; Henry, C. S. Microfluidic ‑ Based Ion ‑ Selective Thermoplastic Electrode Array for Point ‑ of ‑ Care Detection of Potassium and Sodium Ions. Microchim. Acta 2022,
4 Klunder, K. J.; Nilsson, Z.; Sambur, J. B.; Henry, C. S. Patternable Solvent-Processed Thermoplastic Graphite Electrodes. 2017.

Speaker: Vanessa de Ataide - University Sao Paulo
Vanessa graduated in Chemistry (2015) from Presbyterian Mackenzie University. She received her M.Sc. (2018) from the Institute of Chemistry of the University of São Paulo under the supervision of Prof. Dr. Thiago R. L. C. Paixão. She is currently a Ph.D. student with the same supervisor and in the same institution. Her research interests include electrochemical paper-based devices, carbon materials, fabrication of electrochemical sensors using low-cost techniques, and analytical applications involving clinical and environmental interest species. She receives financial support from São Paulo Research Foundation - FAPESP (Grant Number: 2018/14462-0). She is currently doing an internship at Colorado State University under the supervision of Prof. Dr. Charles S. Henry, supported by FAPESP (Grant Number: 2021/10388-2). She is developing carbon-based low-cost electrochemical devices for the detection of Covid-19.