Synthesis of a polydopamaine nanoparticle/bacterial cellulose composite for use as a biocompatible matrix for laccase immobilization

Abstract

Bacterial cellulose has attracted attention as a scaffolding material for enzyme immobilization because of its excellent mechanical properties, nanoporous structure, high purity, and super hydrophilicity. However, the lack of reactive group and the relatively low binding capacity toward biomolecules limit its application. In this study, we have synthesized a polydopamine nanoparticle/bacterial cellulose hybrid material with hierarchical multiscale architecture for enzyme immobilization, via a simple in situ self-assembly of polydopamine nanoparticles on cellulose surface. Commercial enzyme laccases were employed to evaluate the enzyme immobilizability of this hybrid material, and various key parameters of enzyme immobilization such as reaction time, enzyme concentration, temperature and pH were also systematically studied. This hybrid composite displayed excellent enzyme immobilization efficiency (~ 165 mg laccase per g composite), and the immobilized laccase also exhibited better thermostability and operational stability over a broad temperature range as compared with free laccase. By using the immobilized laccase, fast and efficient dye removal ability and good recyclability were achieved during the dye decolorization test, which demonstrated its potential application in various industrial relevant wastewater treatment processes.