Targeted modification of the carbon paste electrode by natural zeolite and graphene oxide for the enhanced analysis of paracetamol

In this work, the targeted modification of carbon paste (CP) by admixing of conductive graphene oxide (GO) and mesoporous natural zeolite with the introduced Ni2+ cations (NiZ), providing electrocatalytic properties, is presented. The performed univariate optimization indicated that 5 % (w/w) of NiZ and GO in the CP is sufficient to ensure a threefold increase in peak current and lower the overpotential of paracetamol (PAR) oxidation, while retaining a low background current and high signal-to-noise ratio. The fabricated CPE/NiZ/GO sensor ensured a linear response in the PAR concentration range from 0.004 to 0.12 mg L−1, advantageously low limit of detection equal to 0.0012 mg L−1 (0.0078 µM), and high stability of recorded signals (RSD = 3 %). Moreover, the proposed analytical method is characterized by good selectivity and robustness to the presence of interference. The usefulness of the CPE/NiZ/GO was verified by the determination of PAR in pharmaceuticals, human urine and serum, delivering acceptable results.