“…PVA is often used as an immobilization matrix because of its inherent nontoxicity, high thermal stability, good biocompatibility and its desirable physical properties such as its elastic nature, good film forming properties, and its high degree of swelling in aqueous solutions -all of which contribute to making it a good matrix for enzyme immobilization [9]. Different methods, such as the cross-linking of PVA [10], freeze-thawed PVA [11], enzyme encapsulation in PVA/silicate hybrid materials [3], have been successfully employed to immobilize the enzyme molecules in various membranes. However, because of the compaction and low-conductivity of the PVA membrane, substrate infiltration and electron transfer between the enzyme membrane and the electrode remains problematic [12].…”