Epoxy Functionalized Carboxymethyl Dextran Magnetic Nanoparticles for Immobilization of Alcohol Dehydrogenase

Microbial inhibition of carboxymethyl dextran (CMD) magnetic nanoparticles (MNPs) was investigated on two different bacterial cultures, Escherichia coli and Staphylococcus aureus, where inhibition properties of CMD-MNPs were confirmed, while uncoated MNPs exhibited no inhibition properties. To such CMD-MNPs, enzyme alcohol dehydrogenase (ADH) from Saccharomyces cerevisiae was immobilized. Later on, CMD-MNPs were functionalized, using an epoxide cross-linker epichlorohydrin (EClH) for another option of ADH immobilization. Residual activities of immobilized ADH onto epoxy functionalized and non-functionalized CMD-MNPs were determined. Effect of cross-linker concentration, temperature of immobilization and enzyme concentration on residual activities of immobilized ADH were determined, as well. With optimal process conditions (4% (v/v) EClH, 4 °C and 0.02 mg/mL of ADH), residual activity of immobilized ADH was 90%. Such immobilized ADH was characterized using FT-IR, SEM and DLS analysis.