Covalently linked, water-dispersible, cyclodextrin: reduced-graphene oxide sheets

Area of Science:

• Materials Science
• Nanotechnology
• Supramolecular Chemistry

Background:

• Reduced-graphene oxide (rGO) is a promising material but often suffers from poor dispersibility in aqueous solutions.
• Cyclodextrins (CDs) are known for their ability to form inclusion complexes with various molecules.
• Combining rGO with β-cyclodextrin (β-CD) could enhance material properties and expand applications.

Purpose of the Study:

• To covalently link β-cyclodextrin (β-CD) cavities to reduced-graphene oxide (rGO) sheets.
• To investigate the dispersibility and fluorescence quenching properties of the functionalized β-CD:rGO sheets.
• To create a water-dispersible material combining the properties of rGO and β-CD.

Main Methods:

• Functionalization of rGO sheets by covalently linking β-CD via an amide linkage.
• Zeta potential measurements to assess dispersibility across a wide pH range (2-13).
• Fluorescence quenching studies of adsorbed planar aromatic and included nonplanar molecules.

Main Results:

• The functionalized β-CD:rGO sheets exhibit significantly improved dispersibility compared to unmodified rGO, over a broad pH range.
• Zeta potential analysis suggests multiple factors contribute to the enhanced dispersibility.
• Effective fluorescence quenching of both planar aromatic molecules on the rGO surface and nonplanar molecules within the β-CD cavities was observed.

Conclusions:

• Covalent linkage of β-CD to rGO creates a stable, water-dispersible hybrid material.
• The β-CD:rGO sheets demonstrate efficient fluorescence quenching capabilities.
• This novel material synergistically combines the hydrophobicity of rGO and β-CD cavities in a single, dispersible platform for potential applications in sensing or separation.