Electrochemical Determination of Papaverine on Mg-Al Layered Double Hydroxide/ Graphene Oxide and CNT Modified Carbon Paste Electrode

A sensitive electrochemical method for the determination of papaverine (PAP) by using Mg-Al layered double hydroxide graphene oxide (LDH-GO) and multiwall carbon nanotubes (MWCNT) immobilized on carbon paste electrode (CPE) has been introduced. Electrochemical behavior of PAP as an antispasmodic was investigated on modified CPE by cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and double step chronoamperometry techniques. Due to the remarkable electrochemical behavior of MWCNT and the high chemical activity of LDH-GO, CNT/LDH-GO/CPE anodic peak current of PAP enhances compared with CNT/CPE and LDH-GO/CPE. The surface morphology of the electrode was studied by the field emission scanning electron microscopy technique. The effect of experimental parameters, such as pH and scan rate on voltammetric response of PAP, was investigated. Maximum current was observed in phosphate buffer pH = 9.0. The electrode reaction followed a diffusion-controlled pathway. The wide dynamic range of concentration (0.10-100 μmol L
^-1
) with a detection limit of 0.04 μmol L
^-1
was obtained for PAP under optimized conditions. This electrode displayed proper reproducibility, stability, and anti-interference. Low cost, easy preparation, high sensitivity, and good selectivity have made the modified electrode suitable for the determination of PAP in urine and plasma matrixes.