Probe-Induced Self-Aggregation of γ-Cyclodextrin: Formation of Extended Nanotubular Suprastructure

Time-resolved fluorescence anisotropy decay analysis, dynamic light scattering (DLS), and transmission electron microscopy (TEM) techniques have been exploited to substantiate and characterize the formation of a substrate-anchored γ-cyclodextrin nanotubular suprastructure in aqueous medium, the diameter and the length of the entity being ∼250 nm and a few micrometers, respectively. Similar aggregation is not observed with α- and β-cyclodextrins. Dimensions of the substrate and the cyclodextrin cavity have been ascribed to control the formation of the substrate-induced elongated aggregates. The report projects a simple way to design nanotubes of variable dimensions with a proper choice of the anchoring probe and the cyclodextrin.