Covalently Linked, Water-Dispersible, Cyclodextrin: Reduced-Graphene Oxide Sheets

Abstract

Reduced-graphene oxide (<i>r</i>GO) sheets have been functionalized by covalently linking β-cyclodextrin (β-CD) cavities to the sheets via an amide linkage. The functionalized β-CD:<i>r</i>GO sheets, in contrast to <i>r</i>GO, are dispersible over a wide range of pH values (2–13). Zeta potential measurements indicate that there is more than one factor responsible for the dispersibility. We show here that planar aromatic molecules adsorbed on the <i>r</i>GO sheet as well as nonplanar molecules included in the tethered β-CD cavities have their fluorescence effectively quenched by the β-CD:<i>r</i>GO sheets. The β-CD:<i>r</i>GO sheets combine the hydrophobicity associated with <i>r</i>GO along with the hydrophobicity of the cyclodextrin cavities in a single water-dispersible material