The effect of ultrasonic irradiation on the morphology of NiO/Co3O4 nanocomposite and its application to the simultaneous electrochemical determination of droxidopa and carbidopa.

The present work deals with the preparation of NiO/Co3O4 nanocomposites in presence of ultrasonic irradiation, and its use in electrochemical determination of Parkinson's drugs. NiO/Co3O4 nanocomposites are prepared using ultrasound assisted method. The impact of ultrasonic irradiation power (0, 75, 150, 300 and 600 W) on the structure and morphology of NiO/Co3O4 nanocomposites was investigated. Various particle morphologies were attained because of the existence of ultrasonic irradiation. The nanoparticles' structure exhibited more uniformity whilst the particles sizes and nanoparticle accumulation was reduced when ultrasonic irradiation power was increased. The NiO/Co3O4 nanocomposite was determined via X-ray diffraction, scanning electron microscopy i.e. SEM as well as energy dispersion X-ray spectroscopy (EDX). Drop casting NiO/Co3O4 nanocomposites suspension on glassy carbon electrode was employed to fabricate the modified glassy carbon electrode (NiO/Co3O4/GCE). The electrochemical studies on the NiO/Co3O4 nanocomposite towards droxidopa and carbidopa were experimented via cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV). The CV examinations displayed increased catalytic behavior of droxidopa because of synergistic impact of the nanocomposite that was bolstered through enhanced material surface roughness. By using differential pulse voltammetry, the droxidopa detection limit and linear range was determined as 0.01 μM and 0.1-500.0 μM, respectively. Also, the adjusted electrode was implemented to ascertain droxidopa in the presence of carbidopa by differential pulse voltammetry. This sensor exhibited long term reproducibility and stability. Droxidopa and carbidopa quantification within biological specimens of fluids i.e. human urine and serum were conducted to validate the suitability in the application of this sensor.