Atomic layer deposition modified track-etched conical nanochannels for protein sensing

Area of Science:

• Biophysics
• Nanotechnology
• Biomolecular detection

Background:

• Nanopore devices are effective for single-molecule biomolecule detection.
• Detecting small, fast-moving protein molecules presents challenges due to poor signal-to-noise ratios.
• Existing methods struggle with efficient and accurate protein sensing at the single-molecule level.

Purpose of the Study:

• To develop and characterize a new nanopore device for sensitive protein detection.
• To improve the signal-to-noise ratio and capture rate for protein translocation events.
• To elucidate the mechanism behind protein-induced current changes in nanopores.

Main Methods:

• Fabrication of track-etched conical nanochannels modified with atomic layer deposition (ALD) Al2O3.
• Utilizing nanopore sensing to detect the transport of protein molecules (bovine serum albumin).
• Analyzing ion transport signals and current changes during protein translocation.

Main Results:

• Demonstrated a high capture rate for bovine serum albumin (BSA) proteins.
• Achieved well time-resolved transport signals with excellent signal-to-noise ratio.
• Observed unusual biphasic current waveshapes, suggesting a novel detection mechanism.

Conclusions:

• ALD-modified nanochannels offer a promising platform for single-molecule protein sensing.
• The developed devices significantly improve protein detection sensitivity and signal quality.
• A proposed mechanism involving ion redistribution explains the observed biphasic signal, advancing nanopore sensing theory.