Conformational gating of DNA conductance

Area of Science:

• Molecular electronics
• Biophysics
• Materials science

Background:

• Deoxyribonucleic acid (DNA) possesses unique electronic and self-assembly properties, making it a candidate for molecular electronics.
• Understanding DNA's electrical properties is crucial for developing novel electronic devices.

Purpose of the Study:

• To investigate the effect of DNA conformation on its electrical conductance.
• To explore the potential of DNA as a switchable component in molecular electronic devices.

Main Methods:

• Experimental manipulation of DNA conformation between B-form and A-form.
• Measurement of electrical conductance of DNA duplexes in different conformations.
• Analysis using a coherence-corrected hopping model.
• Supporting theoretical calculations using ab initio electronic structure methods.

Main Results:

• A reversible, tenfold increase in DNA duplex conductance was observed upon switching from B-form to A-form.
• The conductance switching is controllable via the chemical environment.
• Conductance showed weak length dependencies for guanine-rich sequences.
• Ab initio calculations revealed greater highest occupied molecular orbital dispersion in A-form DNA.

Conclusions:

• DNA can function as a reversible molecular switch for molecular electronics.
• Conformational changes significantly impact DNA's electrical properties.
• Findings contribute to understanding the variability of DNA conductance values in scientific literature.