Poly(L-lysine) Interfaces via Dual Click Reactions on Surface-Bound Custom-Designed Dithiol Adsorbates

Area of Science:

• Surface Chemistry
• Biomaterials Science
• Nanotechnology

Background:

• Poly(L-lysine) is crucial for electrostatic immobilization of biomolecules.
• Developing stable, controlled poly(L-lysine)-modified surfaces is essential for bio-applications.
• Existing methods require optimization for controlled surface attachment.

Purpose of the Study:

• To prepare self-assembled monolayers (SAMs) as platforms for controlled biomolecule attachment.
• To determine parameters for stable poly(L-lysine)-modified SAMs with controlled packing densities.
• To evaluate adsorbate structures for effective polypeptide interface formation.

Main Methods:

• Utilized azide-terminated adsorbates for SAM formation on gold surfaces.
• Employed copper-catalyzed cycloaddition ('click' reaction) to introduce maleimide linkers.
• Used thiol-Michael addition to immobilize cysteine-terminated poly(L-lysine).

Main Results:

• Characterized SAMs using ellipsometry, XPS, PM-IRRAS, and contact angle goniometry.
• Investigated mixed SAMs to understand the effect of azide site dilution on click reaction efficiency.
• Identified optimal adsorbate structures for creating targeted polypeptide interfaces.

Conclusions:

• Demonstrated the effectiveness of bidentate adsorbates for creating biomolecule attachment platforms.
• Validated the two-step immobilization strategy for stable and controlled poly(L-lysine) surfaces.
• Highlighted the potential of click chemistry for advanced bio-interface engineering.