PEG-MODIFIED GLUCOSE-OXIDASE IMMOBILIZED ON A PVA CRYOGEL MEMBRANE FOR AMPEROMETRIC BIOSENSOR APPLICATIONS

Poly(ethylene glycol)-modified glucose oxidase was immobilized in a po ly(vinyl alcohol) cryogel membrane, obtained by a freezing-thawing cyc lic process, to obtain a suitable amperometric glucose sensor, The cov alent linkage between PEG and GOD molecule improved the physical immob ilization of enzyme in the polymeric matrix, by decreasing its loss in time. Sensor behaviour was evaluated electrochemically with a hydroge n peroxide electrode, The glucose content in standard solutions was de termined and linear calibration curves in the 5 x 10(-5)-5 x 10(-3) mo l l(-1) range were obtained. The kinetic parameters in the immobilized system were evaluated and analytical characteristics of sensor, inclu ding stability and influence of pH and temperature, were determined. ( C) 1998 Elsevier Science B.V.