Electrocatalytical oxidation and sensitive determination of acetaminophen on glassy carbon electrode modified with graphene–chitosan composite

The electrochemical behaviors of acetaminophen (ACOP) on a graphene–chitosan (GR–CS) nanocomposite modified glassy carbon electrode (GCE) were investigated by cyclic voltammetry (CV), chronocoulometry (CC) and differential pulse voltammetry (DPV). Electrochemical characterization showed that the GR–CS nanocomposite had excellent electrocatalytic activity and surface area effect. As compared with bare GCE, the redox signal of ACOP on GR–CS/GCE was greatly enhanced. The values of electron transfer rate constant (ks), diffusion coefficient (D) and the surface adsorption amount (Γ⁎) of ACOP on GR–CS/GCE were determined to be 0.25 s− 1, 3.61 × 10− 5 cm2 s− 1 and 1.09 × 10− 9 mol cm− 2, respectively. Additionally, a 2e−/2H+ electrochemical reaction mechanism of ACOP was deduced based on the acidity experiment. Under the optimized conditions, the ACOP could be quantified in the range from 1.0 × 10− 6 to 1.0 × 10− 4 M with a low detection limit of 3.0 × 10− 7 M based on 3S/N. The interference and recovery experiments further showed that the proposed method is acceptable for the determination of ACOP in real pharmaceutical preparations.