Piperazinyl-amide derivatives of N-alpha-(3-trifluoromethyl-benzenesulfonyl)-L-arginine were synthesized as graftable thrombin inhibitors, Their biological activity was evaluated in vitro, against human alpha-thrombin, and in blood coagulation assay. The piperazinyl-amide derivatives were found to inhibit the activity of a-thrombin in the micromolar range. The designed molecules were fixed on poly(ethylene terephthalate) (PET), and poly(butylene terephthalate) (PBT) by wet chemistry treatment (activation of hydroxyl chain-ends) and photochemistry (nitrene insertion by photoactivation of aromatic azide). The protocols were validated by X-ray photoelectron spectroscopy (XPS) and by radiochemical assay (liquid scintillation counting, LSC).