A portable and sensitive dopamine sensor based on AuNPs functionalized ZnO-rGO nanocomposites modified screen-printed electrode

Dopamine (DA) is an important neurotransmitter and one of the biomarkers of psychiatric diseases such as Parkinson's disease and schizophrenia. Therefore, it is urgent to explore an effective method to realize rapid and sensitive detection of DA. In this paper, porous zinc oxide microspheres-functional reduced graphene oxide composites (ZnO-rGO) were successfully prepared by a simple solution method, then gold nanoparticles (AuNPs) were combined by electrodeposition. Zinc oxide porous microspheres-reduced graphene oxide-gold nanoparticles nanocomposites were used to modify the screen-printed electrode (ZnO-rGO-AuNPs@SPE) to fabricate a fast and efficient non-enzymatic electrochemical sensing platform for detecting DA in biological samples. The sensor obtained a good linear range of 0.5 μM to 100 μM and a low detection limit of 0.294 μM at S/N = 3. Additionally, a sensor was applied to the determination of DA in human biological samples, and it showed good stability and reproducibility, making it an excellent candidate material in the field of biosensors.