Membranes with molecular recognition proper-ties were obtained by coagulation in the presence of compounds of biotechnological interest or by modification of non-imprinted membranes with the introduction of imprinted nanoparticles obtained by polymerisation of a monomer(s) in the presence of a stamp molecule (template). The functional binding performances in aqueous medium towards template molecules (uric acid, theophylline, caffeine or proteins) were investigated. Membranes of acrylonitrile-acrylic acid copolymer imprinted with uric acid showed satisfactory recognition capacity and selectivity towards the template (rebinding of uric acid resulted 2.4 times higher than that of theophylline). Porous supports of ethylene-co-vinyl alcohol-dextran blends were obtained using alpha-amylase as template and selective properties were confirmed by a rebinding of the stamp molecule 1.96 times higher than that of albumin. In some cases, recognition properties of methylmethacrylate-co-acrylic acid membranes were enhanced by loading on the surface, or inside the membrane, imprinted cross-linked methylmethacrylate-methacrylic acid nanospheres. The different membranes realised are promising solutions for filtration or adsorption applications in biomedical field or for other biotechnological uses where biomimetic behaviour in water media is requested. (c) 2006 Elsevier B.V. All rights reserved.