Date of Completion


Embargo Period



Dr. Carolyn Teschke, Dr. Victoria Robinson

Field of Study

Molecular and Cell Biology


Master of Science

Open Access

Open Access


Enzymes are key molecular machines that catalyze biologically important chemical reactions. The use of these powerful catalysts has recently been investigated for more industrial applications such as bio-fuel cells, glucose sensors, and biomedical engineering purposes. The main limiting factor of these versatile macromolecules is the stability concerns under conditions of elevated temperature or unfavorable pH. Chemical modification via charge manipulation of one of the most widely used enzymes in industrial research, glucose oxidase, is conducted in this report to stabilize the functional structure and improve the catalytic longevity under thermally taxing conditions. Further enhancement in solution stability is achieved by combining the catalytically efficient modified enzymes with flexible, stable, graphene oxide sheets. The thermal insulating and electrically conductive features of graphene oxide make it attractive scaffolding for the chemically modified glucose oxidase molecules to be anchored to, creating highly stable functional bio-hybrids. Activity of the chemically modified enzymes was observed to be above 50% for almost 40 days at 40°C, which could lead to profound improvement in the application of bionanomaterials where reactions catalyzed at high temperatures are necessary. This facile approach has can be used to successfully control affinity by manipulation of charge of the protein and can be expanded to further applications in bio-nanotechnology.

Major Advisor

Dr. Challa Vijaya Kumar