Design of Nanomaterial-Based Sensors for Enhanced Halogen Bonding

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Halogen bonding (XB) is a directional, noncovalent interaction crucial for applications like sensor design.
• XB strength depends on bond distances and angles, influencing binding energies.
• Optimizing XB geometries for enhanced interactions is an underexplored area.

Purpose of the Study:

• To investigate and experimentally demonstrate how molecular geometries and bond angles enhance halogen bonding interactions.
• To develop a sensitive sensor for detecting cyclohexanone, a byproduct of explosives.
• To explore the use of functionalized nanomaterials in halogen bonding-based sensing.

Main Methods:

• Utilized self-assembled monolayers (SAMs) and gold nanoparticle (Au-NP) interfaces functionalized for XB interactions.
• Incorporated halogen-terminated perfluorinated ligands onto Au-NPs (monolayer-protected clusters) and SWCNTs for enhanced XB donor capability.
• Employed DFT and vapor studies targeting cyclohexanone (CH) within nanomaterial composite films.

Main Results:

• Developed a sensing interface using functionalized Au-NPs and SWCNTs that exhibits strong XB interactions.
• Achieved detection limits for cyclohexanone (CH) below 10 ppm, outperforming similar systems.
• Demonstrated the effectiveness of the XB system in both solution and gas-phase sensing.

Conclusions:

• The study successfully enhanced halogen bonding interactions through specific ligand design and interface engineering.
• The developed sensor demonstrates high sensitivity and rapid detection capabilities for explosive byproducts.
• This research highlights the potential of XB systems for creating advanced field sensors for explosives detection.