Electrochemical sensor based on laser-induced graphene and CeO2 for sensitive and selective dopamine detection

In this study, we developed a highly sensitive electrochemical sensor for dopamine (DA) detection using a fast and simple CO2 laser scribing technique. The sensor was fabricated by scribing a polyimide (PI) film coated with a CeO2 precursor, forming laser-induced graphene (LIG) with anchored CeO2 particles. The CeO2 particles enhanced the electrochemical surface area (ESA) to 3.35 cm2 and reduced the charge transfer resistance (Rct) to 761.8 Ω. Our sensors demonstrated a linear response to DA concentrations from 0 to 10 μM, with a sensitivity of 25.09 μA/μM·cm2 and a detection limit (LOD) of 0.38 μM. Additionally, it exhibited good selectivity, with responses to glucose (GU), ascorbic acid (AA), and uric acid (UA) being less than 55% of the DA response. These results suggest that this sensor is highly suitable for DA detection in biosensing applications. Furthermore, the simple and rapid fabrication process opens possibilities for broader applications in electrochemical sensing.