Self-assembled monolayers on gold of β-cyclodextrin adsorbates with different anchoring groups

Area of Science:

• Supramolecular Chemistry
• Surface Science
• Materials Science

Background:

• Cyclodextrins are versatile host molecules with unique cavity structures.
• Developing stable and well-ordered monolayers on surfaces is crucial for various applications.
• Tailoring surface properties requires precise control over molecular assembly.

Purpose of the Study:

• To design and synthesize multivalent β-cyclodextrin-based adsorbates with diverse anchoring groups.
• To investigate the formation and properties of self-assembled monolayers (SAMs) on gold surfaces.
• To understand how different anchoring groups influence monolayer characteristics.

Main Methods:

• Synthesis of β-cyclodextrin derivatives functionalized with iodide, nitrile, amine, isothiocyanate, methyl sulfide, and isocyanide.
• Characterization of the resulting monolayers using contact angle measurements, SPR, PMIRRAS, XPS, and electrochemistry.

Main Results:

• The choice of anchoring group significantly impacted adsorption kinetics, monolayer thickness, and stability.
• Different functional groups led to variations in surface packing density and the number of anchoring points.
• Monolayers exhibited close contact of the cyclodextrin cavity to the gold surface, influenced by the anchoring group.

Conclusions:

• Multivalent β-cyclodextrin adsorbates can form stable monolayers on gold surfaces.
• The chemical nature of the anchoring group is a critical factor in controlling monolayer properties.
• Chemical modification of adsorbates provides a route to engineer surface characteristics for specific applications.