The surface of meltblown poly(butylene terephthalate) (PBT) nonwoven was modified by photochemistry using the photolinker O-succinimidyl 4-azido-2,3,5,6-tetrafluorobenzoate for the introduction of activated ester functions and then coupling of molecular probes or biomolecules. Approximately 4000 pmol of (L)-4,5-[(3)H]-lysine was fixed per PBT sample (1.13 cm(2)) and measured by liquid scintillation counting. The method consisted in a two-step process: (a) coating of the clip (0.05 mg/sample) on the fibrous surface of the PBT followed by UV irradiation (30 min, 254 nm) and (b) coupling of amine-terminated molecules (10(-3) M in phosphate buffer-CH(3)CN [1/1, v/v], 20 h). Moreover, about 2000 pmol of (3)H-lysine can be immobilized on the PBT surface after UV irradiation (without clip) by aminolysis reactions with the created oxygenated functions. The derivatizations (via the clip and UV irradiation only) were stable after long-term heating at 100 degrees C in water or under steam-sterilization conditions. They induce neither modifications of the nonwoven morphology nor cytotoxicity. This method was applied for the grafting of peptides Gly-Arg-Gly-Asp-Ser and Gly-Gly-Gly-Gly-Gly to perform blood filtration experiments and to retain the leukocytes. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 5087-5099, 2011