BACKGROUND: The performances of four types of glucose oxidase (GOD) immobilization materials based on poly(vinyl alcohol) (PVA) were compared. The matrices of interest were chernically-linked PVA, freeze-thawed PVA cryogel, tetramethoxysilane (TMOS) sol-gel-PVA hybrid material, and alumina sol-gel-PVA hybrid material. RESULTS: Overall, the membranes showed good sensitivity except for the chemically cross-linked PVA. However, the main differences with the enzyme immobilization methods were enzyme leakage and values of K-m(app). CONCLUSION: Freeze-thawed PVA-GOD membranes and TMOS-PVA, which showed satisfactory sensitivity and adequate value of K-m(app), were quite promising as support materials for immobilizing GOD. (c) 2007 Society of Chemical Industry.