The triskelion peptide conjugate 1, having a Trp-Trp dipeptide unit on the three arms, was synthesized and studied for the interaction of peptide-based soft structures with metal ions, by fluorescence and microscopic analyses. We observed that fluorescence was significantly quenched upon addition of Cu(II) metal ions, whereas the addition of other metal ions also caused moderate to insignificant changes in the fluorescence emission, suggesting specificity of this triskelion peptide 1 for Cu(II) ions. The addition of Cu(II) and other metal ions also altered the morphology of preformed vesicles obtained from triskelion peptide 1 in a concentration-dependent fashion, as observed from microscopic analysis. Such metal-responsive soft structures may find potential use as novel materials for delivery and sensing applications. © 2007 Elsevier Ltd. All rights reserved.