Modified Au Nanoparticles/Imprinted Sol-Gel/Multiwall Carbon Nanotubes Pencil Graphite Electrode as a Selective Electrochemical Sensor for Papaverine Determination

In this paper, a simple, accurate, and sensitive electrochemical sensor was developed for rapid determination of Papaverine hydrochloride (Pap) as vasodilators to relax veins and arteries. A modified electrode that was coated with a multiwall carbon nanotube (MWCNTs), a thin film of molecularly imprinted polymer (MIP), and deposition of Au-nanoparticles (AuNPs) was developed to prepare sensor. This sensing layer is constructed on a treated surface of pencil graphite electrode (PGE) via cyclic voltammetry. The characteristics of the constructed sensor for Pap determination was followed using square wave voltammetry, electrochemical impedance voltammetry, cyclic voltammetry, and field-emission scanning electron microscopy. The interaction between the imprinted sensor (AuNP/MIP-sol-gel/f-MWCNT/PGE) and Pap molecules as the target molecule was characterized in the potential range of -0.30 to -0.7 V versus Ag/AgCl (saturated) in 50-μmol L
^-1
K
₃
[Fe(CN)
₆
] as a probe. This sensor verified high sensitivity, selectivity, and quick response toward Pap. The calibration curve for the sensor was plotted in two linear range from 0.001 to 0.1 and 0.1 to 5.0 μmol L
^-1
, with a detection limit of 0.4 nmol L
^-1
. The relative standard deviation for six replicate determinations of 1-μmol L
^-1
Pap was 3.6%. Finally, the modified electrode was successfully applied to determine Pap in human serum and urine matrices.