Novel electrochemical sensor based on Fe3O4-ZrO2-graphene oxide for determination of dopamine

Graphene oxide (GO) was first prepared by an improved Hummers method; Fe3O4, ZrO2, and corresponding metal oxide-GO composite materials were synthesized by a hydrothermal method. The electrochemical performance of as-prepared materials modified glassy carbon electrode (GCE) was investigated by cyclic voltammetry (CV). The ternary Fe3O4-ZrO2-GO composite modified GCE was used as the electrochemical sensor for the dopamine (DA) detection. The CV test showed that the Fe3O4-ZrO2-GO composite modified GCE had a good response to DA with good stability and reproducibility. Electrochemical impedance spectroscopy (EIS) illustrated that Fe3O4-ZrO2-GO/GCE exhibited the lower R-ct value (14.11 omega). Differential pulse voltammetry (DPV) test demonstrated that the ternary composite has excellent anti-interference ability. The linear relationship by differential pulse voltammetry for Fe3O4-ZrO2-GO/GCE was I-pa(mu A) = 0.2552x + 0.0056 (R-2 = 0.9804) with the sensitivity of 3.649 mu A mu M-1 cm(-2) and detection limit of 0.1562 mu M in the ranges of 0.5 - 15 mu M. The developed electrochemical sensor was successfully applied to the DA detection in human serum with satisfactory recovery rate. The possible synergistic amplification effect brought from Fe3O4, ZrO2, and GO for DA detection was proposed based on experimental results.

Automated summary

Graphene oxide (GO) was synthesized using an improved Hummers method, followed by hydrothermal synthesis of Fe3O4, ZrO2, and their composites. The Fe3O4-ZrO2-GO composite modified electrode exhibited a strong response to dopamine (DA) with good stability and reproducibility.