Integration of an Open EWOD Structure and Printed Electrochemical Sensors on Common Digital Microfluidic Platform

Digital microfluidics (DMF) technology provides high-precision and flexible liquid manipulation capabilities for lab-on-a-chip (LOC) systems, enabling complex biochemical reactions and detection analyses within a compact space. Electrowetting-on-dielectric (EWOD), one of the most widely used actuation mechanisms in DMF devices, is favored for its simplicity, controllability, rapid response, and cost-effectiveness. However, due to challenges in fabricating sensors on hydrophobic surfaces, reports on EWOD chips integrated with biosensors remain limited. In this work, we successfully integrated electrochemical sensors into EWOD chips via plasma treatment for surface modification. The plasma-treated EWOD device maintained excellent droplet actuation performance (movement time <8 s) and achieved glucose detection in the 0-0.6 mM range using the embedded sensor. The limit of detection was determined to be 0.056 mM (S/N = 3). This EWOD chip with integrated printed electrochemical sensors represents a promising tool for diverse biochemical analyses.