A method for making a medical device having at least one biomolecule immobilized on a substrate surface is provided. One method of the present invention includes immobilizing a biomolecule comprising an unsubstituted amide moiety on a biomaterial surface. Another method of the present invention includes immobilizing a biomolecule on a biomaterial surface comprising an unsubstituted amide moiety. Still another method of the present invention may be employed to crosslink biomolecules comprising unsubstituted amide moieties immobilized on medical device surfaces. Additionally, one method of the present invention may be employed to crosslink biomolecules comprising unsubstituted amide moieties in solution, thereby forming a crosslinked biomaterial or a crosslinked medical device coating.