Production of carbon paste working electrode with three-dimensional printer for use in biosensor studies

In this study, the aim was to produce low-cost, disposable new carbon paste electrodes for use in biosensor designs and to demonstrate their applicability as biosensors. The literature indicates that biosensor systems have been developed for the quantitative analysis of various compounds, and for this purpose, solid electrodes, carbon paste electrodes, screen-printed electrodes, indium tin oxide electrodes, and similar electrode types have been used in electrochemical measurements. Each of these electrodes has significant usage drawbacks. Particularly in sensors where various enzymes and tissues are used as biocomponents, the use of carbon paste electrodes is common. The cavity of carbon paste electrodes needs to be cleaned after each use; however, impurities often remain in the cavity after cleaning, affecting subsequent measurements. This study aimed to address this issue by producing new disposable and low-cost carbon paste working electrodes. To achieve this, disposable carbon paste electrodes were designed using SolidWorks software. The best design was selected and manufactured using the Formlabs 3+ 3D Printer. For the potentiostat connection of the printed electrodes, conductive wires made of copper, gold, tin-plated copper, and platinum were used, and their electrochemical behaviors were examined using impedance spectroscopy. The produced electrodes were used in the design of a laccase-based amperometric biosensor for catechol determination. The reproducibility and repeatability characteristics of four different developed biosensors were evaluated. All measurements were performed using a potentiostat/galvanostat with a three-electrode system consisting of a platinum counter electrode, an Ag/AgCl reference electrode, and a working electrode within a cell containing a buffer solution. As a result, in this study, low-cost, disposable carbon paste working electrodes were produced that offer ease of use, rapid measurement, high sensitivity, and excellent reproducibility and repeatability with the use of different conductive wires.