Supramolecular Solubilization of Cyclodextrin-Modified\nCarbon Nano-Onions by Host–Guest Interactions

Abstract

Small carbon nano-onions (CNOs, 6–12\nshells) were prepared\nin high yields and functionalized with carboxylic groups by chemical\noxidation and reacted with βCD-NH₂ to yield CNOs\ndecorated with βCDs. A biocompatibile dextran polymer with graphted\nferrocene groups was employed for the supramolecular self-assembly\non the βCD-CNO surfaces. The βCDs act as hosts and the\npolymer ferrocene groups as guests (Fc-Dex) by the formation of inclusion\ncomplexes. After their assembly these nanostructures were soluble\nin aqueous solutions. The resulting product was characterized by transmission\nelectron microscopy (TEM), thermogravimetric analysis (TGA), and FT-IR\nand Raman spectroscopies. Moreover, the deposition of successive layers\non the surface of the particles was monitored using DLS measurements\nand zeta potentials. Through-space interactions between the Fc moieties\nand the CNO cores and the influence of an additional dextran-βCD\nouter layer were measured electrochemically.