Thermoplastic electrodes as a new electrochemical platform coupled to microfluidic devices for tryptamine determination

• Published in: Analytica chimica acta 2021-02, Vol.1147, p.116-123
• Main Authors: Pradela-Filho, Lauro A., Araújo, Diele A.G., Takeuchi, Regina M., Santos, André L., Henry, Charles S.
• Format: Article
• Language: English
• Subjects: Biogenic amine; Carbon; Carbon black; Electrochemical determination; Electrochemical Techniques; Electrodes; Humans; Lab-On-A-Chip Devices; Paper-based microfluidic device; Polycaprolactone; Tryptamines
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2020.12.059

This study reports a new electrochemical method for tryptamine determination using a paper-based microfluidic device and a thermoplastic electrode (TPE) as an amperometric detector. Tryptamine (Tryp) is a biogenic amine present in drinks and foods. Even though this compound has some beneficial effects on human health, the ingestion of foods with high concentrations of Tryp may be detrimental, which justifies the need for monitoring the Tryp levels. The TPEs were made from 50% carbon black and 50% polycaprolactone and characterized by cyclic voltammetry, demonstrating enhancement in the analytical response compared to other carbon composites. TPEs also showed a better antifouling effect for Tryp compared to conventional glassy carbon electrodes. Once characterized, the electrodes were incorporated into the microfluidic device to determine Tryp in water and cheese samples using amperometry. A linear range was achieved from 10 to 75 μmol L−1 with limits of detection and quantification of 3.2 and 10.5 μmol L−1, respectively. Therefore, this work shows promising findings of the electrochemical determination of Tryp, bringing valuable results regarding the electrochemical properties of thermoplastic composites. [Display omitted] •Fouling resistant thermoplastic electrodes (TPEs) for tryptamine determination.•50% carbon black and 50% polycaprolactone were used to prepare the electrodes.•TPE-μPAD can ensure fast analyses and generate less waste.•Possibility of reusing the electrodes by simply polishing them after several uses.•A simple strategy to eliminate ascorbic acid interference.