New Generation Polymeric Nanospheres for Catalase Immobilization

Monosize poly(2-hydroxyethyl methacrylate-co-N-methacryloly-L-histidinemethylester) [mon-poly (HEMA-MAH)] nanospheres were prepared via surfactant-free emulsion polymerization method. L-Histidine groups of the mon-poly(HEMA-MAH) nanospheres were chelated with Fe3+ ions. Mon-poly(HEMA-MAH) nanospheres were characterized by Fourier transform infrared spectroscopy, proton NMR, and scanning electron microscopy. Particle size of the mon-poly(HEMA-MAH) nanospheres was measured by Zeta Sizer. Elemental analysis of MAH for nitrogen was estimated as 0.94 mmol/g polymer. The catalase immobilized onto the mon-poly(HEMA-MAH)-Fe3+ nanospheres resulted in increasing the enzyme stability with time. Optimum operational temperature for both immobilized preparations was the same, and the temperature profiles of the immobilized preparations were significantly broader. It was observed that enzyme could be repeatedly adsorbed and desorbed on the mon-poly(HEMA-MAH)-Fe3+ nanospheres without loss of adsorption capacity or enzymic activity. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 962-970, 2009