Gating electrical transport through DNA molecules that bridge between silicon nanogaps

Area of Science:

• Nanotechnology
• Molecular Electronics
• Biophysics

Background:

• Advancements in molecular electronics seek to utilize biological molecules for novel electronic functionalities.
• Semiconducting properties of DNA are crucial for its integration into electronic devices.
• Fabricating stable and functional molecular-scale electronic components remains a significant challenge.

Purpose of the Study:

• To investigate the electronic properties of DNA molecules when integrated into a three-terminal device.
• To determine if DNA can exhibit semiconducting behavior suitable for electronic applications.
• To explore the modulation of electrical current through DNA by gate voltage.

Main Methods:

• Preparation of silicon-based three-terminal electrodes with a 120 nm source-drain nanogap.
• Bridging both ends of 400 bp long, mixed-sequence DNA molecules via chemical bonds across the nanogap.
• Characterization of the electronic transport properties using I-V measurements and gate voltage modulation.

Main Results:

• Successfully fabricated DNA electronic devices on silicon-based electrodes.
• Observed S-shaped current-voltage (I-V) curves, indicating unique electronic transport characteristics.
• Demonstrated that the electrical current through the DNA molecules can be effectively modulated by the gate voltage.

Conclusions:

• DNA molecules, when integrated into a three-terminal device, function as p-type semiconducting nanowires.
• The study confirms the potential of DNA as a functional component in molecular electronic devices.
• Gate voltage modulation of current highlights the controllability of DNA-based electronics.