Electrochemical sensing platform based on two-dimensional Ni-MOF and ionic liquid modified carbon paste electrode for simultaneous determination of levodopa and cabergoline

In the present work, simple method was utilized for the preparation of two-dimensional Ni-metal organic framework nanosheets (2D Ni-MOF NSs). Characterization techniques, including Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM) were applied to characterize the as-prepared 2D Ni-MOF NSs. Then, carbon paste electrode (CPE) modified with 2D Ni-MOF NSs and ionic liquid (IL) was used as sensing platform for voltammetric determination of levodopa. A considerable enhancement in the current response of levodopa was observed at the 2D Ni-MOF NSs/ILCPE compared to other CPEs. After optimization of conditions, the current response recorded at 2D Ni-MOF NSs/ILCPE linearly increased with an increase in levodopa concentration in the range from 0.09 to 365.0 µM, corresponding to a limit of detection of 0.03 µM. Also, the developed sensor showed significant electrocatalytic activity toward the oxidation of levodopa and cabergoline and provided two well-separate oxidation peaks to determine levodopa and cabergoline simultaneously. Moreover, the 2D Ni-MOF NSs/ILCPE presented good and efficient practicability with satisfactory recoveries (97.3–104.6%) and low RSD values of less than 3.6% for the determination of levodopa and cabergoline in real samples.