Directly grown of 3D-nickel oxide nano flowers on TiO2 nanowire arrays by hydrothermal route for electrochemical determination of naringenin flavonoid in vegetable samples

Abstract

A novel an electrochemical sensor is constructed based on three-dimensional Nickel oxide nano flowers (3D-NiO) and TiO2-nanowire arrays (TiO2NWA) by hydrothermal route. Initially TiO2-NWA were produced on titanium foil using hydrothermal method in the presence of 1.0 M NaOH solution at 180 °C for 20 h, then 3D-nickel oxide nano (NiO) flowers (up to 3 µM) are directly grown on TiO2 NWA using hydrothermal reaction in the presence of glucose, urea and nickel acetate mixer solution at 150 °C for 5 h, followed by N2 gas assisted annealing at 500 °C for 2 h. The resultant nanostructures are characterized by CV, XRD, FESEM-EDX and TEM. The as prepared electrodes are used as electrochemical sensors for investigating electrochemical behavior of naringenin (NRG) flavonoid. Further differential pulse voltammetry is used to determine the NRG in vegetable (tomato and ginger) samples at optimized conditions, such as accumulation potential, time, the applied sample volume, pH of the buffer and the step potential. The finest oxidation peaks are observed for NRG in acidic condition (phosphate buffer solution) at around 0.35 V. The obtained oxidation peaks were observed at low current values over the concentration of 1.50 × 10−8 M to 2.35 × 10−4 M with lower detection limit of 0.025 nM for NRG. Mainly the presence of carbon (glucose) enhanced the conductivity and surface area of the as prepared electrode (NiO/TiO2NWA). The nano composite modified electrode (NiO/TiO2NWA) displays good stability, high sensitivity and reproducibility. The recommended method is effectively applied an economical and simple sensor for the present investigation. Keywords: Ti foil, Hydrothermal method, TiO2 nanowires, Nickel oxide nano flowers, NaOH, Naringenin and cyclic voltammetry