Properties and applications of proteins encapsulated within sol–gel derived materials

The last decade has seen a revolution in the area of sol–gel-derived materials since the demonstration that these materials can be used to encapsulate biological species such as enzymes, antibodies and other proteins in a functional state. The interactions between the biomolecule and the inorganic, organic or hybrid nanocomposite material determines the degree to which the biomolecule retains its native properties, and such interactions can be tuned to provide optimised biomaterials that are suitable for a variety of applications. Typical applications of sol–gel derived biomaterials include selective coatings for optical and electrochemical biosensors, stationary phases for affinity chromatography, immunoadsorbent and solid-phase extraction materials, controlled release agents, solid-phase biosynthesis, and unique matrices for biophysical studies. Through careful selection of precursors and additives, these materials can be designed for specific applications, and can produce useful, robust devices with good analytical parameters of merit. Indeed, current advances in the development of nanocomposite and mesostructured materials suggest that major improvements in bioimmobilisation are on the horizon, and should result in substantial improvements in bioanalytical devices over the next decade.