Application of cellulase-polyamidoamine dendrimer-modified silica for microwave-assisted chitosan enzymolysis

Polyamidoamine dendrimer (PAMAM) is one of a number of dendritic polymers with a precise molecular structure, high geometric symmetry, and a large number of terminal groups. In this study, PAMAM was grafted onto the surface of silica by microwave irradiation and characterized by Fourier transform infrared spectroscopy and elemental analysis. A novel immobilized cellulase was developed based on enzyme immobilization onto the prepared PAMAM-grafted silica and applied in microwave-assisted chitosan enzymolysis. The results show that the efficiency of cellulase immobilization increased with increasing generations of PAMAM. A high enzymatic hydrolysis efficiency was obtained for a 7 mg ml−1 chitosan solution at pH 6.2 and 50 °C with 40 W microwave-assisted enzymolysis (20 min) compared with a conventional enzymolysis protocol (3 h). The experimental results indicate that this rapid and efficient enzymolysis method combines the advantages of both PAMAM and microwave-assisted technology, which can be adapted to high-throughput enzyme assay in biochemical and clinical research.