SUMMARY
To obtain glucose biosensors based on glucose oxidase (GOx), the enzyme can be immobilized on the sensitive surface of a glass electrode by different techniques: deposition on membranous support (cellophane or other macromolecular material) or entrapment in a matrix. Deposition on membranous support also involves cross-linking with glutaraldehyde or entrapment in silica gel, following the sol-gel procedure. The aim of this preliminary work was to study the influence of cellophane replacement with a PVA based membranous support on the glucose biosensor performance. The data obtained at pH measurements of buffer solutions with cellophane and PVA membranous supports respectively, show that the PVA based membrane assures superior performances of the biosensor for low glucose concentrations determination (about 10-4 M). These results allow the transition to an improved immobilization technique, namely the enzyme entrapment in membranous material.