The interaction between biopolymers and metal nanoparticles (AgNPs) is a key element in the development of biomimetic nanomaterials with applications in catalysis, delivery, and recognition. Here we report a facile method for the functionalization of AgNPs by N-substituted glycine oligomers, "peptoids." Based on the established affinity between phenanthroline ligand and Ag(0), we synthesized a peptoid bearing 1,10-phenanthroline at the N-terminus (PHP). Treatment of AgNPs that were pre-stabilized by citrate ions, with PHP, leads to the formation of aggregates as suggested by UV-vis spectroscopy. Transmission electron microscopy (TEM) revealed that the replacement of citrate ions by PHP yields spherical assemblies of AgNPs. These peptoids/AgNPs hybrids, as well as the ability of functional biomimetic oligomers to mediate the assembly of metal nanoparticles, hold potential for applications in sensor materials, biology, and catalysis.