Scalable Fabrication of Electrochemical Sensors via Inkjet Printing of Functionalized Graphene for Pesticide Detection

Nanomaterials are widely employed to enhance the performance of electrochemical sensors by modifying electrode surfaces. Traditionally, screen-printed electrodes are manually coated with nanomaterial dispersions using the drop-casting method, which suffers from poor reproducibility and limited reusability due to inconsistencies in deposition. In this study, we introduce a novel electrochemical sensor based on nitrogen-doped graphene acid (NGA), deposited via inkjet printing. This approach provides uniform, reproducible, and mechanically stable NGA coatings with significantly reduced material consumption (~3 vs. ~15 µg) compared to drop-casting. The NGA-modified electrodes exhibit enhanced electrochemical performance, as confirmed by a four-fold decrease in charge transfer resistance and a 2.5-fold increase in current response. The sensor reliably detects imidacloprid, a common neonicotinoid pesticide, with excellent selectivity and long-term stability exceeding 110 days. Inkjet printing enables precise material placement and layer control, ensuring strong adhesion and consistent performance even under mechanical stress and in complex matrices like tap water. This work demonstrates the potential of inkjet printing as a scalable and cost-effective strategy for producing high-performance electrochemical sensors.