Ag2 and Ag3 clusters: synthesis, characterization, and interaction with DNA.

Area of Science:

• Nanomaterials Science
• Biochemistry
• Physical Chemistry

Background:

• Development of subnanometric metal clusters is challenging due to aggregation.
• Understanding metal cluster-DNA interactions is crucial for nanomaterial applications.
• Existing DNA intercalators often have limited binding stability.

Purpose of the Study:

• To synthesize stable subnanometric silver clusters (Ag2 and Ag3) without surfactants.
• To investigate the interaction mechanism between Ag3 clusters and DNA.
• To determine the binding stability and structural impact of Ag3 clusters on DNA.

Main Methods:

• Electrochemical synthesis employing kinetic control for cluster formation.
• Thermodynamic and kinetic measurements to analyze cluster-DNA interactions.
• Theoretical calculations to elucidate the binding mode and DNA structural changes.

Main Results:

• Successful synthesis of exclusively Ag2 and Ag3 clusters via a surfactant-free electrochemical method.
• Demonstrated intercalation of Ag3 clusters into DNA, leading to significant DNA structural distortion.
• Observed exceptionally long lifetimes (2-3 orders of magnitude greater) for intercalated Ag3 clusters compared to ethidium bromide and proflavine.

Conclusions:

• Subnanometric silver clusters can be synthesized using kinetic electrochemical control.
• Ag3 clusters interact with DNA via intercalation, inducing notable structural modifications.
• The prolonged binding stability of Ag3 clusters offers potential advantages over conventional DNA intercalators.