Simple and Rapid Amperometric Monitoring of Hydrogen Peroxide at Hemoglobin-Modified Pencil Lead Electrode as a Novel Biosensor: Application to the Analysis of Honey Sample

Abstract

This paper describes the use of a pencil lead electrode (PLE) covered by hemoglobin (Hb) through a simple and rapid electroless method for the electroreduction of hydrogen peroxide. Some thermodynamic and kinetic parameters such as the number of electrons involved in the rate determining step, n α , transfer coefficient, α, and the total electrons (n) involved in hydrogen peroxide reduction were determined. By attention to the findings, the possible mechanism for the H2O2 reduction at Hb/PLE was suggested. Also, the catalytic rate constant of the electrochemical process k and diffusion coefficient of hydrogen peroxide D were determined. The mean values obtained are 41.9 M−1 s−1 and 1.76 × 10−6 cm2s−1, respectively. Finally, the ability of the electrode for the determination of hydrogen peroxide was investigated. In optimum conditions, the hydrodynamic amperometry was used for the determination of H2O2 at μM concentration level. It is found that the calibration graph is linear in the H2O2 concentration range 5 × 10−6–245 × 10−6 mol L−1 with correlation coefficient of 0.999. The detection limit of the method was about 1 × 10−6 mol L−1. This biosensor was successfully used for the determination of hydrogen peroxide in the tap water and honey samples using amperometric method.