SYNTHESIS CONDITIONS FOR ENCAPSULATING CYTOCHROME-C AND CATALASE IN SIO2 SOL-GEL MATERIALS

The encapsulation of biological molecules in sol-gel materials has led to the development of a new class of chemical and biomedical sensors. The influence of sol-gel synthesis conditions on the stability, chemi cal function, and enzymatic reactivity for horse heart cytochrome c an d bovine liver catalase encapsulated in silica sol-gel materials was s tudied. The effects of synthesis pH, alcohol/alkoxide ratio, and buffe r type were examined using UV-Vis absorption spectroscopy for cytochro me c-doped materials and gasometric analysis for assays of catalase in gels. In general, the behavior of the proteins encapsulated in silica gels mirrored their behavior in solution suggesting that the stabilit y limiting factor for encapsulating these biological molecules is dete rmined by the solution stability of the protein. In the case of catala se, the results indicate that the silica gel stabilizes the encapsulat ed enzyme to higher methanol concentrations.