Peroxidase‐catalyzed electrochemical assay of hydrogen peroxide: A ping–pong mechanism

In view of the great importance of determination of hydrogen peroxide in many scientific fields and industrial applications and the attractive operational simplicity of potentiometric approach for the enzymatic assay, the kinetics of horseradish peroxidase–catalyzed electrochemical assay of H₂O₂ was studied in this work at 25°C. All kinetic characteristics were determined by the double reciprocal Lineweaver–Burk and (primary and secondary) double reciprocal Hanes–Woolf plots. The results confirmed that the reaction follows a ping–pong mechanism. The Michaelis–Menten constants for H₂O₂ and 4‐fluorophenol were K_m = 0.081 ± 0.001 mM and K^4‐FP_m = 0.185 ± 0.002 mM, respectively. The maximum rate was also estimated to be V_max = 0.182 ± 0.002 mM min^?1 (at 25 ± 0.05°C). © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 699–704, 2012