(113b) Enzyme Immobilization in Chemical Microsystems at Louisiana Tech

The use of microfluidics for studying enzyme immobilization using layer-by-layer nano self-assembly will be presented. The highly controlled liquid/solid interface due to the laminar regieme present in microfluidics is ideal for these studies. Urease has been immobilized on silicon microchannel walls to catalyze the reaction of urea to ammonia. The Berthelot procedure is used to directly measure the ammonium ion concentration of the effluent to determine product conversion. Enzyme activity and stability is very sensitive to the choice of polyelectrolytes used for immobilization and will be discussed. Results of Quartz Crystal Microbalance studies and protein assay measurements will also be presented.