Screen Printed Carbon Paste Electrochemical Sensor of Lab on a Chip for Depressive Substance Analysis

This research introduces the design and performance assessment of a screen-printed electrowetting-on-dielectric (EWOD) microchip specifically engineered for detecting compounds associated with depression. The microchip features a two-part T-junction EWOD layout, which includes a silver electrode layer paired with a polydimethylsiloxane (PDMS) dielectric layer. Located at the end of the T-junction is an integrated electrochemical sensor composed of three main elements: a screen-printed graphene/carbon working electrode, a counter electrode, and a silver/silver chloride (Ag/AgCl) reference electrode. The electrodes were produced through a stepwise screen-printing process, while the PDMS dielectric was formed by spin coating. Cyclic voltammetry (CV) was employed to identify electroactive species related to depressive disorders. The results demonstrate that the embedded electrochemical sensor offers high accuracy and reliability for analyzing depression-linked analytes.