The grafting of a polyethylene (PE) surface layer implanted with 156 keV Xe+ ions at fluences of 3.10(13) to 1.10(15) cm(-2) with alanine was studied with the aim to prepare prospective materials for biological experiments. It was shown by different spectroscopical methods that alanine adds onto double bonds or reacts with radicals created by ion irradiation on the polymer chain. The grafting occurs in the whole ion-damaged polymer layer. (C) 2000 John Wiley & Sons, Inc.