Detection of neurotransmitter (Levodopa) in vegetables using nitrogen-doped graphene oxide incorporated Nickel oxide modified electrode

Nitrogen-doped graphene supported with Nickel oxide (N-GE/NiO) nanocomposite were prepared to develop the sensor for determination of L-dopa. The structure and morphology of the N-GE/NiO nanocomposite was characterized by powder X-ray diffraction (PXRD), Fourier transform Infra-red (FT-IR), Raman spectroscopy, thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and the electrochemical response of L-dopa was also studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in phosphate buffer solution (PBS) at pH 7.0. The experimental results recommended that N-GE/NiO nanocomposite electro-oxidation response is greater than that of the bare electrode. The DPV results reports of L-dopa were increased linearly in the range from 0.03 - 386.8 μM with a limit of detection is about 17 nM. Finally, the proposed sensor was applied for the sensitive determination of L-dopa in the vegetable sample and the achieved results were relatively promising.