Properties of the hydrophilic copolymer supporter containing oxirane for immobilized glucose oxidase

Oxirane groups can react with the amino groups of enzyme under mild conditions so that could be immobilized on the surface of copolymer supporter. The macroporous Ferrofluid-GMA-MBAA (FGM) polymer were synthesized by inverse suspension polymerization with glycidyl methacrylate (GMA) as the reactive monomer and N, N′-methylene-bis-acrylamide (MBAA) as the cross-linking agent. Polyvinylpyrrolidone (PVP) was used as the stabilizer monomer and azodiisobutyronitrile (AIBN) was used as the initiator monomer. Fe3O4 was added as magnetofluid to the dispersion medium, ethanol solution. The effects of the amount of magnetofluid and crosslinking agent on the structure properties and the apparent activity of immobilized enzyme were investigated. The recovery rate of apparent relative activity of 90.45% (about 546.23±2.33 U/g) was obtained when the glucose oxidase (GOD) enzyme was immobilized on FGM polymer [w(GMA)=20%, w(ferrofluid)=0.4%, w(MBAA)=40%] at 55°C and pH 8.0. The enzyme activity was nearly 60% of its initial even after being used for 15 times. After a 30-day storage at 4°C, the immobilized enzyme showed little changes in its activity.