Optimization of site specific adsorption of oleylamine capped CuO nanoparticles on MWCNTs for electrochemical determination of guanosine

The electrostatic adsorption method has been developed for the fabrication of oleylamine (OLA) capped CuO nanoparticles with acid functionalized multiwalled carbon nanotubes (MWCNTs) for the electrochemical determination of guanosine (GNO). For OLA-CuO nanoparticles, electrochemical application depends on its stability and electrical conductivity of the GC modified electrode. The OLA-CuO/MWCNTs nanocomposite mixed oxide/hydroxide layer formation avoided via strong electrostatic adsorption. The different wt% loadings of OLA-CuO nanoparticles onto MWCNTs are optimized by Fourier infrared spectra (FTIR) and linear sweep voltammetry (LSV) measurements. The nanocomposite, 30 wt% OLA-CuO nanoparticles loaded MWCNTs exhibited increase in electric conductivity and accelerated the electron transfer as examined by electrochemical impedance spectroscopy (EIS). The OLA-CuO/MWCNTs composite modified glassy carbon electrodes are shown to be good electrocatalytic surfaces for the oxidation of GNO. The GNO oxidation peak currents were linearly proportional to their concentrations in the range from 0.3 to 18.9 μM with sensitivity of 0.675 μA μM−1 and detection limits were to be 0.084 μM.