In this work, we describe the cografting of glycidyl methacrylate and dimethyl acrylamide onto a macroporous polysulfone polymer. Aminophenyl arsenical compounds were covalently attached to the copolymer through epoxy ring add-on reactions followed by a 2-mercaptoethanol activation. Thioredoxin and thioredoxin-fusion proteins were immobilized onto this surface and detected by specific antibody recognition. Preservation of native protein folding was confirmed by the detection of the enzymatic activity of an unstable fusion protein. Immobilized fusion protein onto the modified material maintains the enzymatic activity for a longer time, up to two weeks, against the free protein under the same storage conditions that remains active for 2 days. (C) 2009 Elsevier Ltd. All rights reserved.