Preparation of magnetic chitosan nanoparticles and immobilization of laccase

  • Hua Fang (方华)
  • Jun Huang (黄俊)
  • Liyun Ding
  • Mingtian Li
  • Zhao Chen
Article

DOI: 10.1007/s11595-009-1042-7

Cite this article as:
Fang, H., Huang, J., Ding, L. et al. J. Wuhan Univ. Technol.-Mat. Sci. Edit. (2009) 24: 42. doi:10.1007/s11595-009-1042-7

Abstract

The magnetic chitosan nanoparticles were prepared by reversed-phase suspension method using Span-80 as an emulsifier, glutaraldehyde as cross-linking reagent. And the nanoparticles were characterized by TEM, FT-IR and hysteresis loop. The results show that the nanoparticles are spherical and almost superparamagnetic. The laccase was immobilized on nanoparticles by adsorption and subsequently by cross-linking with glutaraldehyde. The immobilization conditions and characterizations of the immobilized laccase were investigated. The optimal immobilization conditions were as follows: 10 mL of phosphate buffer (0.1 M, pH 7.0) containing 50 mg of magnetic chitosan nanoparticles, 1.0 mg · mL1 of laccase and 1% (v/v) glutaraldehyde, immobilization temperature of 4°C and immobilization time of 4 h. The immobilized laccase exhibited an appreciable catalytic capability (480 units · g−1 support) and had good storage stability and operation stability. The Km of immobilized and free laccase for ABTS were 140.6 and 31.1 μM in phosphate buffer (0.1 M, pH 3.0) at 37 °C, respectively. The immobilized laccase is a good candidate for the research and development of biosensors based on laccase catalysis.

Key words

laccase magnetic chitosan nanoparticles immobilization enzyme activity stability 

Copyright information

© Wuhan University of Technology and Springer-Verlag GmbH 2009

Authors and Affiliations

  • Hua Fang (方华)
    • 1
  • Jun Huang (黄俊)
    • 1
  • Liyun Ding
    • 1
  • Mingtian Li
    • 1
  • Zhao Chen
    • 1
  1. 1.Key Laboratory of Fiber Optic Sensing Technology and Information Processing (Ministry of Education)Wuhan University of TechnologyWuhanChina