Structural Recognition of Triple-Stranded DNA by Surface-Enhanced Raman Spectroscopy

Area of Science:

• Biophysical Chemistry
• Molecular Biology
• Nanotechnology

Background:

• Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for label-free analysis of nucleic acids.
• Interrogating complex nucleic acid tertiary structures beyond the double helix remains a challenge.

Purpose of the Study:

• To report the first structural identification of DNA triplexes using SERS.
• To demonstrate the capability of SERS in discriminating DNA triplex structures from duplex and single-stranded counterparts.

Main Methods:

• Utilizing direct, label-free surface-enhanced Raman spectroscopy (SERS).
• Analyzing characteristic marker bands in the SERS fingerprint.
• Correlating vibrational features with specific structural elements of DNA triplexes.

Main Results:

• Successfully identified unique SERS spectral fingerprints for DNA triplex structures.
• Distinguished triplex structures from duplex and single-stranded DNA based on specific vibrational markers.
• Observed spectral features indicative of base stacking, Hoogsteen hydrogen bonding, and backbone reorganization.

Conclusions:

• Direct SERS analysis enables unambiguous structural identification of DNA triplexes.
• This method expands SERS applications in nucleic acid analysis.
• Potential impact on sensing, molecular biology, and drug design.