Pluronic triblock copolymers were entrapped on the surface of polyaniline (PANI) films by first immersing the latter in N-methylpyrrolidinone (NMP) solutions of one of the Pluronics for a short time. This softened the surface of the films and allowed the Pluronic molecules to entangle with PANI segments of the swollen film on the surface. Further, the films were taken out from the NMP solution and dipped into water, which is a nonsolvent for PANI. The rapid surface deswelling of PANI by the water resulted in the entrapment of the Pluronic on its surface, with the hydrophilic blocks toward water and the hydrophobic block imbedded in the PANI films. The modified PANI obtained was examined by X-ray photoelectron spectroscopy, water droplets contact angles, scanning electron microscopy, and wide angle X-ray diffraction. The surface of the Pluronic entrapped PANI films became more hydrophilic than the hydrophobic PANI films and decreased the amount of bovine serum albumin protein adsorbed on them. This means that, by reducing the biofouling, the life of the modified polyaniline film can be extended when the latter is employed as a biosensor. (C) 2003 Elsevier Inc. All rights reserved.