Glassy carbon electrode modified with a nanocomposite of multi-walled carbon nanotube decorated with Ag nanoparticles for electrochemical investigation of Isoxsuprine

A highly sensitive voltammetric sensor is prepared using multi-walled carbon nanotube decorated with silver nanoparticles (AgNPs-MWCNTs) and is applied for the determination of Isoxsuprine (ISOX). The characterization of the prepared nanocomposite is performed using energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscope (TEM), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry techniques. The electrochemical behavior of ISOX is studied on the surface of the modified electrode by linear sweep and cyclic voltammetry methods. Under the optimized conditions such as pH of the supporting electrolyte, accumulation time and amount of the casted modifier, a significant electrochemical improvement is observed toward the electro-oxidation of ISOX on the surface of AgNPs-MWCNTs glassy carbon electrode (AgNPs-MWCNTs/GCE), in comparison to MWCNTs/GCE and bare GCE. At the surface of the modified electrode two oxidation peaks are observed for ISOX at potentials around 0.63 V (peak I) and 0.82 V (peak II) in BR buffer solution of pH 7.0. By using two anodic peaks of ISOX, two linear dynamic ranges of 0.04-5.0 μmol L−1 and 0.2-5.0 μmol L−1 with detection limits of 12 nmol L−1 and 60 nmol L−1are obtained for peaks I and II, respectively. The modified electrode showed a simple fabrication procedure, high sensitivity, stability and good reproducibility in response to ISOX. The AgNPs-MWCNTs/GCE is successfully applied for the accurate determination of trace amounts of ISOX in pharmaceutical and clinical preparations.