Abstract

A simple and strong electrostatic adsorption of oleylamine (OLA) capped nickel oxide (NiO) nanoparticles (oleylamine-amine group) onto the acid functionalized multiwalled carbon nanotubes (MWCNTs) (-COOH group) through coulombic interaction, leads to the construction of OLA-NiO/MWCNTs nanocomposite. The optimum loading of OLA-NiO nanoparticles on to the acid functionalized MWCNTs is investigated by Fourier transform infrared spectroscopy. Moreover, the optimum amount of loading and stability of the modified electrodes were studied by using linear sweep voltammetry and conductivity of optimum loadings are also studied by electrochemical impedance spectroscopy. OLA-NiO/MWCNTs nanocomposite was fabricated on glassy carbon electrode for the electrochemical determination of riboflavin (RF) at nanomolar levels. The results show a dynamic linear range of 0.009-55.9 mu M with excellent sensitivity of 0.489 mu A mu M-1 and the limit of detection was found to be 1 nM (S/N - 3). The developed OLA-NiO/MWCNTs composite decorated GC exhibited good sensitivity, stability, and reproducibility for the determination of RF in differential pulse voltammetry. The OLA-NiO/MWCNTs/GC modified electrode was applied for the determination of RF in pharmaceutical formulation tablet and syrup samples.