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 detecting dopamine (DA) using a simple and fast CO 2 laser scribing technique. The UV/Ozone-treated polyimide (PI) film coated with CeO 2 precursor was scribed by the CO 2 laser to synthesize the electrochemical sensor (UV-LC). The CeO 2 particles were well anchored on the laser-induced graphene (LIG) surface, enhancing the electrochemical surface area (ESA) from 1.31 cm 2 in LIG to 3.35 cm 2 in UV-LC. Also, the CeO 2 particles were affected by the reducing charge transfer resistance (R ct ) from 1281 Ω to 761.8 Ω which is the LIG and UV-LC value, respectively. UV-LC demonstrated a linear response to DA concentrations from 0 to 10 μM, with a sensitivity of 25.09 μA/μM·cm 2 and a detection limit (LOD) of 0.38 μM which is the higher and lower value compared to other metal oxide-based DA sensors. Additionally, UV-LC exhibited good selectivity with glucose (GU), ascorbic acid (AA), and uric acid (UA) being less than 55 % of the DA current response. These results suggest this sensor is highly suitable for DA detection in biosensing applications. Furthermore, this simple and rapid fabrication process opens possibilities for various electrochemical devices