Enzyme nanoparticles show promise in the ability to have their properties tailored through immobilization, which provide advantages such as enhanced stability and facile separation from reaction mixtures. We are exploring two types of enzyme immobilization: cross-linking to a magnetic nanoparticle core and binding to stimuli responsive polymers. Cross-linking methods, while reducing the overall enzymatic activity, retained activity through multiple cycles and up to forty days. Enzyme immobilized magnetic nanoparticles of different sizes will be tested for activity, long-term stability and recoverability. We will elucidate the dependence of the size of the complexes on activity and recoverability. Magnetic nanoparticles, varying in size from 20 – 80 nm have been synthesized and characterized via TEM imaging. We are immobilizing cellulases to demonstrate the application of the immobilization concept on cellulose hydrolysis. Currently, a single cellulase is being used but future experiments will involve more complex mixtures of endo – and exo-cellulases for optimal hydrolysis.