Results from activity studies of celullase immobilized on glass and silicon will be presented.  Polyethylenimine (PEI) and polystyrenesulfonate (PSS) were the polyelectrolytes used for the nano self-assembly process.  Conversion of cellobios to glucose was monitored in a batch reactor to determine a first order rate constant.  The efficacy of the enzyme layers were monitored over a period of days to weeks.  Surface charge modification using Self-Assembled Monolayers (SAM) was utilized to enhance the layering on glass.