Silver Nanoclusters Serve as Fluorescent Rivets Linking Hoogsteen Triplex DNA and Hairpin-Loop DNA Structures

Area of Science:

• Nanotechnology
• Biochemistry
• Materials Science

Background:

• DNA nanostructures are crucial for creating DNA nanomachines.
• Silver nanoclusters (AgNCs) are highly emissive and can be stabilized by DNA secondary structures.
• Understanding the interplay between DNA and nanomaterials is key for designing advanced nanodevices.

Purpose of the Study:

• To investigate the pH-dependent fluorescence of AgNCs within DNA nanostructures.
• To explore the potential of AgNCs as nanoscale rivets for DNA assembly.
• To design novel DNA nanostructures using noncanonical base pairing.

Main Methods:

• Encapsulation of AgNCs within Hoogsteen triplex DNA structures.
• pH-dependent fluorescence measurements.
• Fluorescence lifetime and small-angle X-ray scattering analyses.
• In-gel electrophoresis to study DNA dimerization.

Main Results:

• AgNCs encapsulated in Hoogsteen triplex DNA exhibit tunable fluorescence (on/off) in response to pH changes.
• AgNCs function as nanorivets, linking different DNA nanostructures like triplex and hairpin DNA.
• The formation of AgNCs-riveted DNA dimers influences the photophysical properties and fluorescence.
• Heterodimers formed by triplex and hairpin DNA with AgNCs emit orange fluorescence.

Conclusions:

• AgNCs can be used as pH-responsive fluorescent probes within DNA nanostructures.
• AgNCs serve as effective nanorivets for assembling DNA nanostructures via noncanonical interactions.
• This approach enables the design of advanced DNA origami beyond Watson-Crick base pairing.