Influence of gamma irradiation on a natural source of peroxidase and its effect in the reagentless amperometric biosensor for hydrogen peroxide

Abstract

Peroxidase was extracted from a natural source (turnip) and irradiated with ⁶⁰Co (0.1 kGy). It was then used in the construction of biosensors for hydrogen peroxide determination, in order to study the effect of the gamma irradiation on the performance of the biosensors. The biosensors were constructed using two immobilization procedures: cross-linking with glutaraldehyde and covalent binding through carbodiimide. The biosensor prepared using covalent binding through carbodiimide showed a higher sensitivity for H₂O₂. A good enhancement in stability and sensitivity was obtained for the biosensors from irradiated material, when compared to biosensors prepared with non-irradiated enzyme. However, the initial linear response range (1.0 to10.0 mmol dm⁻³) and response time (0.5 s) were equal with or without irradiation.