Electrocatalytic measurement of H2O2 concentration using bis(N-2-methylphenyl alicyldenaminato)copper(II) spiked in a carbon paste electrode

Abstract

The electrochemical behavior of a bis( N -2-methylphenyl-salicyldenaminato)copper(II) complex spiked in a carbon paste electrode (BMPSCu-CPE) and its electrocatalytic reduction of H 2 O 2 were examined using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry. Cyclic voltammetry was used to study the redox properties of BMPSCu-CPE at various potential scan rates. The apparent charge transfer rate constant and the transfer coefficient for the electron transfer between BMPSCu and the carbon paste electrode (CPE) were 1.9 ± 0.1 s –1 and 0.43, respectively. BMPSCu-CPE had excellent electrocatalytic activity for H 2 O 2 reduction in 0.1 mol/L phosphate buffer solution (pH 5.0), and it decreased the overpotential by 300 mV as compared to CPE alone. The diffusion coefficient and kinetic parameters such as the heterogeneous catalytic electron transfer rate constant and electron transfer coefficient for the reduction of H 2 O 2 at the BMPSCu-CPE surface were also determined using electrochemical methods. Differential pulse voltammetry showed two linear dynamic ranges of 1.0–10.0 and 10.0–300.0 μmol/L and a detection limit of 0.63 μmol/L H 2 O 2 . The BMPSCu-CPE has excellent reproducibility and long term stability, and it was successfully applied for the determination of H 2 O 2 in two pharmaceutical samples: an antiseptic solution and a hair dying cream. A Cu(II) complex (BMPSCu) used for the electrocatalytic reduction of H 2 O 2 gave excellent activity. It successfully detected H 2 O 2 in two pharmaceutical samples.