Self-Adhesive Mask and Homemade Carbon Ink: Turning Unusable Screen-Printed Electrodes into a New Voltammetric Sensor

Screen-printed carbon electrodes (SPCEs) are widely employed in sensing due to their low cost, especially the model DRP-110. However, their disposable nature limits their long-term applications. In this work, we present a sustainable methodology for recovering the electrode model DRP-110-U75. Unusable SPCEs were made usable again after employing a stencil-printing approach. After recuperating the electrodes (Re-SPCE), characterization experiments upon the Re-SPCEs have indicated similar morphological aspects and catalytic ability when compared to as-purchased SPCEs. As a proof of concept, voltammetric analysis of dopamine (DOP) in artificial urine and tryptophan (TRP) in supplement capsules was successfully employed, exhibiting limits of detection of 2.15 and 0.2 μmol L^-1 for DOP and TRP, respectively. These results confirm that the proposed method can extend the life cycle of SPCEs.