6-APA derivatives were considered as selective labels for the construction of bifunctional linkers dedicated to the oriented immobilization of proteins on materials. Sulbactam-like compounds (i.e., 6-β-sulfonamido-penam sulfones) and penicillin G—like compounds (i.e., para-substituted 6-β-phenylacetamido-penams) were prepared and tested as irreversible inhibitors of representative β-lactamases and D,D-peptidases, respectively. The activity of the modified antibiotics was preserved despite their substitution with various anchoring arms. The (2-nitro-4,5-dimethoxy)-benzyl esters revealed of particular interest due to their capacity to acylate BlaR-CTD without deprotection.