Multiscale Modeling Reveals Synergistic Rectification in DNA-Coralyne Complexes by Environmental Symmetry Breaking...

Area of Science:

• Molecular electronics
• Condensed matter physics
• Biophysics

Background:

• Molecular rectification, a key electronic function, typically relies on asymmetric molecular structures or interfaces.
• DNA-coralyne complexes (cor-DNA) show significant rectification despite apparent molecular symmetry, challenging existing theories.

Purpose of the Study:

• Investigate the mechanism behind rectification in symmetric cor-DNA systems.
• Explain the role of molecular structure, electrode geometry, and ionic environment in charge transport.

Main Methods:

• Utilized a multiscale computational framework combining electrostatics, molecular dynamics, and quantum transport.
• Explicitly modeled electrode geometry and the ionic environment alongside the cor-DNA molecules.

Main Results:

• The cor-DNA molecule itself does not intrinsically break symmetry for charge transport.
• Symmetry breaking originates from a nonuniform electric field and asymmetric electric double-layer response.
• The intercalated coralyne acts as a resonant bridge, enabling rectification through synergy between the external potential and electronic states.

Conclusions:

• Rectification in cor-DNA is driven by an interplay between the symmetric molecular scaffold and an asymmetric environment, not intrinsic molecular asymmetry.
• This mechanism explains rectification's persistence regardless of molecular orientation and its absence in pristine DNA.
• The rectification is tunable, controlled by the intercalator's energy alignment and coupling strength, offering a pathway for designing molecular devices.