Förster resonance energy transfer within single chain nanoparticles

Area of Science:

• Polymer Chemistry
• Supramolecular Chemistry
• Nanotechnology

Background:

• Single chain nanoparticles (SCNPs) are advanced polymer architectures formed by intramolecular crosslinking.
• SCNPs show promise in catalysis, drug delivery, and sensor applications.
• Detecting the folded state of SCNPs is crucial for understanding their function.

Purpose of the Study:

• To introduce a novel Förster Resonance Energy Transfer (FRET) based methodology.
• To optically evidence the intramolecular folding of single polymer chains into SCNPs.
• To establish a fluorescence-based readout for SCNP formation.

Main Methods:

• Utilized a molecular FRET pair comprising bimane and nitrobenzoxadiazole (NBD) moieties.
• Synthesized low dispersity polymers functionalized with NBD units.
• Exploited bimane units for inducing intramolecular chain collapse and SCNP formation.

Main Results:

• Demonstrated that proximity of bimane and NBD units upon SCNP folding leads to a strong FRET signal.
• Observed a clear fluorescence readout indicating the folded state of the single chain nanoparticles.
• Validated the FRET system's performance across different solvent environments.

Conclusions:

• The FRET-based method provides a direct optical signal for SCNP folding.
• This approach simplifies the monitoring of SCNP formation without complex analytical tools.
• Opens new possibilities for real-time observation of SCNP conformational changes.