Comparative study of hydrogel-immobilized L-glutamate oxidases for a novelthick-film biosensor and its application in food samples

Novel, thick-film biosensors have been developed for the determination of L -glutamate in foodstuffs. The sensors were prepared by immobilization of L- glutamate oxidase by using polycarbamylsulfonate-hydrogel on a thick-film s ensor. L-Glutamate oxidases obtained from Streptomyces sp. with different d egree of purification were compared with their characteristic response to L -glutamate at different conditions and for their specificity, inhibition, a nd storage properties. These sensors were applied to determine monosodium g lutamate in soy sauce samples and show good correlation with colorimetric m ethod.