Constructing biopolymer-inorganic nanocomposite through a biomimetic mineralization process for enzyme immobilization

Abstract

Inspired by biosilicification, biomimetic polymer-silica nanocomposite has aroused a lot of interest from the viewpoints of both scientific research and technological applications. In this study, a novel dual functional polymer, NH2-Alginate, is synthesized through an oxidation-amination-reduction process. The "catalysis function" ensures the as-prepared NH2-Alginate inducing biomimetic mineralization of silica from low concentration precursor (Na2SiO3), and the "template function" cause microscopic phase separation in aqueous solution. The diameter of resultant NH2-Alginate micelles in aqueous solution distributed from 100 nm to 1.5 μm, and is influenced by the synthetic process of NH2-Alginate. The size and morphology of obtained NH2-Alginate/silica nanocomposite are correlated with the micelles. NH2-Alginate/silica nanocomposite was subsequently utilized to immobilize β-Glucuronidase (GUS). The harsh condition tolerance and long-term storage stability of the immobilized GUS are notably improved due to the buffering effect of NH2-Alginate and cage effect of silica matrix.