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 CO2 laser scribing technique. The UV/Ozone-treated polyimide (PI) film coated with CeO2 precursor was scribed by the CO2 laser to synthesize the electrochemical sensor (UV-LC). The CeO2 particles were well anchored on the laser-induced graphene (LIG) surface, enhancing the electrochemical surface area (ESA) from 1.31 cm2 in LIG to 3.35 cm2 in UV-LC. Also, the CeO2 particles were affected by the reducing charge transfer resistance (Rct) from 1281 S2 to 761.8 S2 which is the LIG and UV-LC value, respectively. UV-LC demonstrated a linear response to DA concentrations from 0 to 10 mu M, with a sensitivity of 25.09 mu A/mu M center dot cm2 and a detection limit (LOD) of 0.38 mu M 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.