Development of a silica-based double-network hydrogel for high-throughput screening of encapsulated enzymes

A new silica-organic, double-network hydrogel was prepared from a mixture of silica nanoparticles, sodium silicate, and acrylamide to enable biomolecule encapsulation in a one-pot reaction, overcoming the brittleness of the silica matrix. The optimal composition of the hydrogel was 1: 4 (v/v) acrylamide: silicate. The mechanical strength of the double-network hydrogel was almost twice that of a hydrogel prepared from only silica hydrogel. As a result of the hydrogel's increased strength, biomolecules encapsulated within the hydrogel also exhibited improved activity and durability. Trypsin, pepsin, and urease were each encapsulated within double-network hydrogels, and these encapsulated biomolecules showed good enzymatic activities, which were retained for several months. Therefore, the hydrogel was suitable for encapsulation of biomolecules for preparation of biodevices, such as bioreactors and biosensors.