For the first time, the catalytic activity of phenobarbital (PB) in presence of acetaminophen (AC) was studied at the surface of modified electrode which prepared by incorporation of multi-walled carbon nanotube (MWCNT) and Pt-nanoparticles into a paste matrix. Preparation of this electrode was very simple and modified electrode showed an excellent character for electrocatalytic oxidization of acetaminophen and phenobarbital. Using differential pulse voltammetry (DPV), a highly selective and simultaneous determination of AC and PB has been explored at the modified electrode. Differential pulse voltammetry peak currents of AC and PB increased linearly with their concentrations at the ranges of 0.5–100 M and 0.4–60 M, respectively. Also, the detection limits for AC and PB were 0.17 M and 0.1 M, respectively. The method has been found selective and successfully implemented for the determination of AC and PB in human urine and pharmaceutical samples using standard addition method. The electrode exhibited an efficient catalytic response with good reproducibility and stability.
