Surface Functionalisation of Self-Assembled Quantum Dot Microlasers with a DNA Aptamer.

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Colloidal quantum dots (CQDs) are promising for laser applications.
• Supraparticle lasers offer unique optical properties.
• Surface functionalization is key for targeted applications.

Purpose of the Study:

• To functionalize CQD supraparticle lasers with thrombin binding aptamer (TBA-15).
• To investigate the impact of functionalization on laser performance.
• To explore potential applications in biosensing.

Main Methods:

• Self-assembly of CdSSe/ZnS core/shell CQD supraparticles via emulsion technique.
• Surface modification through ligand exchange and EDC/NHS coupling for TBA-15 attachment.
• Characterization using zeta potential and Fourier transform IR spectroscopy.
• Assessment of laser functionality and oscillation thresholds.

Main Results:

• Successfully synthesized microsphere-shaped CQD supraparticles (7.3 ± 5.3 µm) emitting at 630 nm.
• Confirmed TBA-15 attachment to the CQD supraparticle surface.
• Maintained lasing functionality (627-635 nm) post-functionalization.
• Achieved low laser oscillation thresholds for both oleic acid- and TBA-coated microspheres.

Conclusions:

• Surface functionalization of CQD supraparticle lasers with TBA-15 is feasible.
• The functionalization process preserves the lasing properties of the CQD supraparticles.
• This work demonstrates a pathway for developing aptamer-functionalized lasers for potential biosensing applications.