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

Peroxidase was extracted from a natural source (turnip) and irradiated with Co-60 (0.1 kGy). It was then used in the construction of biosensors for hy drogen peroxide determination, in order to study the effect of the gamma ir radiation on the performance of the biosensors. The biosensors were constru cted using two immobilization procedures: cross-linking with glutaraldehyde and covalent binding through carbodiimide. The biosensor prepared using co valent binding through carbodiimide showed a higher sensitivity for H2O2. A good enhancement in stability and sensitivity was obtained for the biosens ors 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 irradiati on.