Preparation and characterization of magnetic duolite-polystyrene composite particles for enzyme immobilization

Duolite A568, which is a good support for enzyme immobilization was processed with magnetite and polystyrene by a solvent evaporation method. The most appropriate polyvinyl alcohol and sodium dodecyl sulphate contents of dispersion medium and process time were determined as 1 g/300 mL, 0.5 g/300 mL and 1-2 h respectively, to obtain maximum immobilized enzyme activity. These magnetic duolite-polystyrene particles were characterized as high spin complex with the g factor of 3.5 and as ferromagnetic. Pectinex Ultra SP-L was used as a model enzyme and it is found that 0.41 muL of enzyme was immobilized on 1 9 of particles. (C) 2003 Elsevier Ltd. All rights reserved.