One‐step preparation of organic‐inorganic hybrid capsules based on simultaneous gelation and silicification

Abstract

Enzyme encapsulation within alginate capsules usually suffers from low encapsulation efficiency and leakage of enzyme. In this study, alginate‐aminosilane hybrid capsules with high encapsulation efficiency, good retention and high storage stability of enzyme have been prepared by a novel method, in which viscous solution containing enzyme, calcium chloride as a crosslinker, and 3‐(2‐aminoethylamino)propyltrimethoxysilane as an aminosilane was dripped into alginate solution, facilitating the formation of alginate‐aminosilane hybrid shell at alginate/droplet interface. Results showed that the hybrid capsules could encapsulate formate dehydrogenase with molecular weight of 74 kDa with encapsulation efficiency of 98% and have the ability to protect the enclosed enzyme from denaturation by chaotropic effect of calcium ion. Furthermore, the capsules were reused efficiently for 20 cycles without loss of the enzyme activity. The approach developed in this study could evolve as a generic platform of enzyme immobilization for various biotechnological applications.

Keywords

• formate dehydrogenase
• organic‐inorganic hybrid microcapsule
• silane coupling agent
• sodium alginate
• sol‐gel