Acetaminophen (N-acetyl-p-aminophenol or Paracetamol) is an antipyretic and analgesic drug commonly used against mild to moderate pain or for reduction of fever [1]. Nanomaterials due to their high conductivity and great surface area have received significant attention for modification of electrodes which exhibit good electrocatalytic activity towards oxidation of acetaminophen [2]. In this work, we have reported the preparation of copper/multi walled carbon nanotubes hybrid incorporated with ionic liquid/carbon paste electrode (Cu-MWCNT/IL/CPE) for determination of acetaminophen at phosphate buffer solution (pH=7.0). The Cu-MWCNT hybrid was synthesized by dispersion of 0.25 g MWCNT (COOH group) with appropriate amount of CuSO4 solution and subsequent reduction the solution by hydrazine monohydrate. Modification of CPE was performed by hand mixing of graphite powder, Cu-MWCNT hybrid, ionic liquid (1-butyl-3-methyl imidazolium hexafluorophosphate) and viscose paraffin oil. The electrochemical investigations showed that the nanohybrid had electrocatalytic effect on oxidation of acetaminophen with improved current density. The oxidation peak potential of acetaminophen at the surface of Cu-MWCNT/IL/CPE appeared at 410 mV that was about 110 mV lower than that traditional CPE under similar conditions. This modified electrode had detection limit of 9.0×10-7 M using differential pulse voltammetry.
