The development of silica-based sol-gel techniques compatible with the retention of protein structure
and function started more than 20 years ago, mainly for the design of biotechnological devices or biomedical applications.
Silica gels are optically transparent, exhibit good mechanical stability, are manufactured with different
geometries, and are easily separated from the reaction media. Biomolecules encapsulated in silica gel normally retain
their structural and functional properties, are stabilized with respect to chemical and physical insults, and can
sometimes exhibit enhanced activity in comparison to the soluble form. This review briefly describes the chemistry of protein encapsulation
within the pores of a silica gel three-dimensional network, the mechanism of interaction between the protein and the gel matrix, and
its effects on protein structure, function, stability and dynamics. The main applications in the field of biosensor design are described.
Special emphasis is devoted to silica gel encapsulation as a tool to selectively stabilize subsets of protein conformations for biochemical
and biophysical studies, an application where silica-based encapsulation demonstrated superior performance with respect to other immobilization