Ten-atom silver cluster signaling and tempering DNA hybridization

Area of Science:

• Nanotechnology
• Biochemistry
• Molecular Biology

Background:

• Silver clusters with approximately 10 atoms function as molecules, forming within DNA strands.
• These molecular metals exhibit unique electronic properties and spectra sensitive to size, oxidation, and shape.
• Silver clusters can act as DNA adducts, coordinating with DNA hosts.

Purpose of the Study:

• To investigate the characteristics of silver cluster-DNA conjugates for biosensor development.
• To develop a sensitive and selective biosensor using a specific cluster-DNA conjugate.
• To understand the optical and structural changes upon target analyte binding.

Main Methods:

• Synthesis and characterization of a silver cluster-DNA conjugate.
• Spectroscopic analysis (absorption and emission) to monitor changes.
• Investigation of DNA structural modifications (hydrodynamic radius, nucleobase stacking).

Main Results:

• A violet cluster-DNA complex (λmax = 400 nm) was synthesized, stabilized by specific DNA domains.
• Target analytes induced a transformation to a blue-green chromophore (λmax = 490 nm) with strong green emission (λmax = 550 nm).
• The conjugate exhibited reduced hydrodynamic radius and disrupted nucleobase stacking upon analyte binding, inhibiting non-target hybridization.

Conclusions:

• The silver cluster-DNA conjugate functions as a molecular beacon with distinct optical signaling.
• The system demonstrates high sensitivity and stringent discrimination against analogous analytes.
• This approach holds promise for developing advanced biosensing platforms.