MATERIALS SCIENCE AND ENGINEERING SEMINAR Hybrid Materials for Sensing and Catalyst Applications By: Alexandra Snyder Ph.D. Final Examination Advisor: Prof. L. Stanciu ABSTRACT Novel hybrid materials are fabricated with the goal of achieving properties that are superior to those of each component individually. The properties of hybrid materials can be tailored by changing the composition or configuration, making them attractive for use in a wide variety of applications ranging from photovoltaics to drug delivery systems. Here I will discuss the synthesis and characterization of several hybrid material systems and their evaluation as photocatalysts or electrochemical sensors. Specifically, the surface chemistry and charge of polyelectrolyte microspheres were varied in order to investigate their effect on the immobilization configuration of two model enzymes for amperometric biosensors. Graphene was incorporated into enzyme-based and enzyme-free sensors in order to enhance electron transfer and amperometric sensitivity. In addition, TiO2 nanoparticles were dispersed throughout a cellulose nanofiber matrix to form photocatalytically active films for the degradation of organic molecules in water. The surfaces of the films were subsequently modified by Au and Ag nanoclusters in order to improve mechanical properties and enhance photocatalysis in simulated sunlight. Date: Thursday, July 11, 2013 Time: 10:00 A.M. Place: HAMP 1113 Lisa Stacey Secretary/Development Assistant Purdue University School of Materials Engineering 765/494-4100