3D cloves bud like Gd doped ZnO strewn rGO hybrid for highly selective determination of l-dopa in the presence of carbidopa and ascorbic acid

An electrochemical sensor using three dimensional (3D) cloves bud like gadolinium doped ZnO nanoflowers strewn reduced graphene oxide (GZO@rGO) modified glassy carbon electrode was proposed for the sensitive and selective detection of l-dopa. The GZO@rGO nanocomposite was synthesized by hydrothermal method and characterized by a variety of analytical and spectroscopy techniques, viz. Field Emission Scanning Electron Microscopy, X-Ray Diffraction, Fourier Transformed Infrared Spectrum and X-ray photoelectron spectroscopy. The electrochemical characterization was evaluated by Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Differential Pulse Voltammetry (DPV). The 3D cloves bud like GZO@rGO hybrid displayed the highest electro-catalytic behaviour for the selective l-dopa detection. Under optimum conditions, the oxidation current response of l-dopa is directly proportional to its concentration ranging from 10 to 100 nM. The sensitivity and limit of detection was calculated as 0.1 μA nM−1 cm-2 and 0.82 nM respectively. Moreover, the proposed electrode offers excellent selectivity, because it can efficiently evade the intervention of carbidopa and ascorbic acid even in the higher concentration. Thus, the reported sensor exhibits accurate determination of l-dopa (in the presence of carbidopa & ascorbic acid) and possesses an excellent real-time application with Mucuna prurita, pharmaceutical and human urine samples.