Kenneth J. Balkus Jr., Rita Huang, Minedys Macias, and Thomas Pisklak. Chemistry, University of Texas at Dallas, P. O. Box 830688, Richardson, TX 75083
Soon after the discovery of mesoporous molecular sieves, we recognized that the mesopore sizes are in the range of biomolecules, including enzymes and redox active proteins. There have been a surprisingly large number of studies directed at bioadsorption/ biocatalysis using mesoporous molecular sieves since our original report. The molecular sieve host materials have largely been composed of silica or surface functionalized silica. However, the family of mesoporous materials has now grown to include a wide variety of compositions and pore architectures. So there is now a potential for generating synergistic behavior between the enzyme and host molecular sieve. Semiconductor compositions such as TiO2 could facilitate photochemical or electrochemical electron transfer reactions. Certain periodic mesoporous organosilicas (PMOs) may also promote electron transfer and function as a co-factor for encapsulated enzymes. By way of example, we have immobilized micropoeroxidase (MP-11) in a variety of mesoporous metal oxides and PMOs as well as metal organic frameworks. Microperoxidase-11 was physically absorbed from solution into the mesoporous materials and characterized by XRD, UV-Vis, CD, FT-IR, N2 adsorption and electrochemistry. The reactivity of supported MP-11 will be described for the conversion of Amplex® UltraRed, methylene blue and methylstyrene to their respective oxidation products.