ENZYMATIC-ACTIVITY OF OXALATE OXIDASE AND KINETIC MEASUREMENTS BY OPTICAL METHODS IN TRANSPARENT SOL-GEL MONOLITHS

Novel synthetic techniques are used for the encapsulation of the enzym es oxalate oxidase and peroxidase in stable, optically transparent por ous silica glass matrices. The large enzymes-are fully immobilized in the porous glass but small molecules such as oxalate ions pass readily through the pores in the glass. The enzymes catalyze the reactions le ading to the formation of a colored dye product. Upon exposure of the doped glass to oxalate solutions, a colored glass is formed. The absor ption spectrum of the colored product and the changes of absorbance wi th time are measured within the glass matrix. The sensitivity and the time-dependence of the response are discussed.