Oligonucleotide-stabilized Ag nanocluster fluorophores

Area of Science:

• Nanotechnology
• Biochemistry
• Materials Science

Background:

• Fluorescent probes are essential in biological imaging and diagnostics.
• Developing probes with enhanced photostability and tunable emission is a key challenge.
• Silver nanoclusters (AgNCs) offer potential as novel fluorophores due to their unique optical properties.

Purpose of the Study:

• To stabilize highly fluorescent silver nanoclusters using single-stranded oligonucleotides.
• To tune the emission color of AgNCs by modifying DNA scaffold sequences.
• To create AgNC-based fluorophores with superior photophysical properties and stability.

Main Methods:

• Utilized DNA microarrays for high-throughput optimization of oligonucleotide scaffold sequences.
• Synthesized and characterized five distinct AgNC emitters with tunable emission wavelengths.
• Performed ensemble and single-molecule fluorescence spectroscopy to evaluate photophysical properties.
• Assessed buffer stability and photostability compared to conventional dyes.

Main Results:

• Developed AgNC fluorophores with tunable emission spanning blue to near-infrared regions.
• Achieved nearly spectrally pure and highly photostable AgNC emitters.
• Demonstrated excellent buffer stability for the oligonucleotide-stabilized AgNCs.
• Oligonucleotide-encapsulated AgNCs showed significantly greater photostability and higher emission rates than cyanine dyes.

Conclusions:

• Single-stranded oligonucleotides are effective scaffolds for creating stable and tunable AgNC fluorophores.
• Optimized AgNCs exhibit superior photophysical performance compared to existing fluorescent dyes.
• These novel AgNC emitters hold great promise for advanced bioimaging and sensing applications.