NafionŽ was modified by mixture casting Nafion with alkyl trimethyl ammonium bromide salts and resuspended as a 5% by weight mixture in ethanol. It has been shown that hydrophobically modified micellar polymers alter the transport properties to the electrode surface as a function of size and charge of redox species. This research compares the enzyme activity of different enzymes after immobilization in modified Nafion membranes. It has been shown in previous research that the increase in hydrophobicity of the Nafion membranes increases the enzyme activity of glucose oxidase, resulting in a more optimal membrane for enzyme immobilization. Alcohol dehydrogenase, aldehyde dehydrogenase, formate dehydrogenase, glucose dehydrogenase, formaldehyde dehydrogenase, and lactic dehydrogenase were immobilized within the hydrophobically modified Nafion and the resulting enzyme activities were compared to measurements of the modified membranes with no enzyme immobilization in a NADH solution. It was shown that the enzymes could be immobilized in the modified Nafion membranes and still have activity. It was also shown that the tetradecyltrimethyl modified polymer is the optimal membrane for immobilizing alcohol dehydrogenase, formaldehyde dehydrogenase, formate dehydrogenase, lactic dehydrogenase, and glucose dehydrogenase. For aldehyde dehydrogenase it was shown that the octyltrimethyl modified Nafion is the optimal membrane for immobilization.