Fluorescent DNA-Templated Silver Nanoclusters from Silver(I)-Mediated Base Pairs

Area of Science:

• Nanotechnology
• Biochemistry
• Molecular Biology

Background:

• Silver nanoclusters (AgNCs) stabilized by double-stranded DNA (dsDNA) exhibit unique properties due to DNA's rigidity and chirality.
• DNA templates offer precise control over AgNC formation and optical characteristics.

Purpose of the Study:

• To synthesize fluorescent AgNCs using dsDNA templates incorporating artificial nucleobases.
• To compare these AgNCs with those derived from DNA containing C:C mismatches.
• To develop a method for detecting specific DNA sequence variations.

Main Methods:

• Introduction of a novel imidazole-silver(I)-cytosine (Im-Ag^I-C) base pair into dsDNA.
• Formation and characterization of AgNCs using UV/Vis, fluorescence, and circular dichroism spectroscopy.
• Investigation of AgNCs' optical properties and aggregation behavior.

Main Results:

• Fluorescent AgNCs were successfully synthesized using dsDNA with artificial nucleobases.
• The resulting AgNCs form chiral aggregates with dsDNA, with optical properties dependent on DNA sequence.
• A method for detecting cytosine insertions in DNA duplexes was demonstrated.

Conclusions:

• Artificial nucleobases in dsDNA templates can yield functional fluorescent AgNCs.
• The sequence-dependent optical properties of these AgNCs enable specific DNA sequence detection.
• This approach provides a novel tool for molecular diagnostics and biosensing.