BiFeO3 perovskite/reduced graphene oxide nanocomposite as a novel modifier for electrochemical detection of dopamine in real samples

Abstract

Dopamine (DA) is a fundamental catecholamine neurotransmitter and fluctuating its concentration level in human body may leads to neurodegeneration. Therefore, it is important to assess the DA levels in human biological fluids. This project studied the preparation of a novel nanocomposite containing BiFeO₃ perovskite nanoparticles and reduced graphene oxide (rGO) by hydrothermal methodology and its application as a modifier for the fabrication of modified glassy carbon electrode; BiFeO₃-rGO/GCE, toward the detection of DA in real samples. The physicochemical characterizations of prepared materials and modified electrode were examined by scanning electron microscopy, energy-dispersive X-ray spectrometry, transmission electron microscopy, X-ray diffraction, Raman and Fourier-transform infrared spectrometry, and electrochemical methods. The electrochemical investigations indicated that the BiFeO₃-rGO greatly improved the electrocatalytic activity of modified electrode toward the DA oxidation, thereby improving sensing performance. The BiFeO₃-rGO/GCE was used as a sensor for detection of DA by differential pulse voltammetry. The developed sensor in the optimum conditions showed two dynamic linear ranges of 1–100 μM and 100–1000 μM with limits of detection as 0.35 μM. The sensor also exhibited high selectivity, sensitivity, reproducibility and stability. Finally, the prepared sensor was utilized for electrochemical detection of DA in real samples with acceptable results (average recovery>97%) and compared with the commercial immunosorbent test (ELISA).