Formulation of organic and inorganic hydrogel matrices for immobilization of beta-glucosidase in microfluidic platform

The aim of this study was to formulate silica and alginate hydrogels for immobilization of beta-glucosidase. For this purpose, enzyme kinetics in hydrogels were determined, activity of immobilized enzymes was compared with that of free enzyme, and structures of silica and alginate hydrogels were characterized in terms of surface area and pore size. The addition of polyethylene oxide improved the mechanical strength of the silica gels and 68% of the initial activity of the enzyme was preserved after immobilizing into tetraethyl orthosilicate-polyethylene oxide matrix where the relative activity in alginate beads was 87%. The immobilized beta-glucosidase was loaded into glass-silicon-glass microreactors and catalysis of 4-nitrophenyl beta-D-glucopyranoside was carried out at various retention times (5, 10, and 15 min) to compare the performance of silica and alginate hydrogels as immobilization matrices. The results indicated that alginate hydrogels exhibited slightly better properties than silica, which can be utilized for biocatalysis in microfluidic platforms.