Towards nanometer-spaced silicon contacts to proteins.

Area of Science:

• Bioelectronics
• Materials Science
• Nanotechnology

Background:

• Investigating electronic transport in biomolecules is crucial for advancing bioelectronic systems.
• Existing methods often lack stable, reproducible contacts for protein electronic measurements.

Purpose of the Study:

• To report a novel vertical nanogap device (VND) structure with all-silicon contacts.
• To demonstrate the VND's capability for investigating electronic transport processes in bioelectronic systems, specifically with proteins.

Main Methods:

• Fabrication of VNDs from silicon-on-insulator substrates using photolithography and wet etching.
• Creation of nanogaps (4-8 nm) using selective recess etching of the buried oxide layer.
• Functionalization with cytochrome c protein and subsequent current-voltage measurements.

Main Results:

• Successful trapping of gold nanoparticles for device functionality verification.
• Significant increase (several orders of magnitude) in junction conductance after protein immobilization.
• Conductance increase was reversible upon heating above the protein's denaturation temperature.

Conclusions:

• VNDs provide non-destructive, permanent semiconducting contacts to proteins.
• The Si-protein-Si configuration enables parallel conductance measurements through numerous protein molecules.
• This technology offers a new platform for studying protein electronic transport in a symmetrical configuration.