Optimization of Polymerization Parameters for Enhanced Paracetamol Selectivity of Poly(1,4-diaminobenzene) Membrane Electrodes

The electrochemical polymerization of 1,4-diaminobenzene in an aqueous KCl electrolyte at a controlled potential of 0.600 V resulted in the formation of an adherent poly(1,4-diaminobenzene) (PDB) film on a gold electrode. This polymeric membrane demonstrated selective permeability for paracetamol while effectively blocking ascorbic acid interference. A comprehensive investigation of polymerization parameters, including film thickness, monomer concentration, electrolyte concentration, and applied polymerization potential, was conducted to optimize the permselective characteristics of the PDB film. Voltammetric studies revealed that a polymeric film with a thickness corresponding to 7 mC charge exhibited the highest selectivity for paracetamol while completely suppressing ascorbic acid oxidation signals. Further analysis demonstrated that the optimal polymerization potential was 0.600 V vs. Ag/AgCl, where the peak oxidation current for paracetamol was maximized. Monomer and electrolyte concentrations were also optimized, with the best response obtained at 50 mM 1,4-diaminobenzene and 100 mM KCl. The findings suggest that the optimized PDB film functions as an effective permselective membrane, enabling highly sensitive and selective electrochemical detection of paracetamol. This approach offers a cost-effective and robust alternative to conventional sensors, addressing issues such as low sensitivity, poor stability, and the need for noble metal electrodes. The optimized polymer membrane holds potential for applications in pharmaceutical analysis and biomedical sensing, where precise and interference-free detection of paracetamol is essential.