Dopamine Determination with a Biosensor Based on Catalase and Modified Carbon Paste Electrode with Zinc Oxide Nanoparticles

Determination level of dopamine (DA) is very important in medicine and disease diagnostic. In presented research, a biosensor designed based on catalase (CAT) and modified carbon paste electrode (CPE) with zinc oxide (ZnO) nanoparticles for Determination level of dopamine by electrochemical methods. Synthesized ZnO nanoparticles were studied by X-ray diffraction (XRD), UV-visible spectrophotometer and atomic force microscopy (AFM). Electrochemical studies were done with cyclic voltammetry (CV) and constant potential amperometry (CPA) experiments. A pair of well-defined redox peaks was observed at the CAT / ZnO Nps/ CPE with The formal potential (Eo) equal to + (92.5 ± 1) mV. Zinc oxide nanoparticles could play a key role in creates the CAT CV response and facile electron transfer between CAT and CPE. The CAT/ZnO Nps/CPE showed a good sensitive state towards oxidation of DA. The designed biosensor showed a good stability and retains its 91% activity after 21 days.