Selective Metal-Ion-Mediated Vesicle Adhesion Based on Dynamic Self-Organization of a Pyrene-Appended Glutamic Acid

Vesicles with dynamic membranes provide an ideal model system for investigating biological membrane activities, whereby vesicle aggregation behaviors including adhesion, fusion, fission, and membrane contraction/extension have attracted much attention. In this work we utilize an aromatic amino acid (pyrene-appended glutamic acid, PGlu) to prepare nanovesicles that aggregate to form vesicle clusters selectively induced by Fe3+ or Cu2+, and the vesicles transform into irregular nano-objects when interacting with Al3+. Vesicle clusters have better stability than pristine vesicles, which hinders the spontaneous morphological transformation from vesicles into lamellar nanosheets with long incubation period. The difference between complexation of Fe3+ and Al3+ with vesicles was studied by various techniques. On the basis of metal ion–vesicle interactions, this self-assembled nanovesicle system also behaves as an effective fluorescent sensor for Fe3+ and Al3+, which cause fluorescence quenching and enhanced exci...