Molecular Rectifiers with a Very High Rectification Ratio Enabled by Oxidative Damage in Double-Stranded DNA.

Area of Science:

• Molecular electronics
• Biophysics
• Genetics

Background:

• DNA is susceptible to oxidative damage, primarily guanine oxidation to 8-oxoguanine (8oxoG).
• Oxidative damage can alter DNA's electronic properties, with implications for cellular function and disease.

Purpose of the Study:

• To investigate the charge migration properties of DNA with varying concentrations and locations of 8-oxoguanine.
• To explore the potential of oxidatively damaged DNA in constructing molecular electronic devices.

Main Methods:

• Utilized a multiscale multiconfigurational methodology.
• Employed molecular dynamics, density functional theory, and kinetic Monte Carlo simulations.
• Analyzed charge transport properties in native and damaged double-stranded DNA (dsDNA) sequences.

Main Results:

• Demonstrated tunable rectifier properties in dsDNA containing 8-oxoguanine.
• Discovered negative differential resistance in a fully oxidized Drew-Dickerson sequence.
• Identified 8-oxoguanine as a charge sink, protecting the genome from further oxidative damage.

Conclusions:

• Oxidatively damaged DNA can be engineered into efficient molecular diodes and switches.
• The electronic properties of DNA are significantly influenced by the presence and location of 8-oxoguanine.
• This research opens avenues for novel molecular electronic applications and understanding DNA repair mechanisms.