Buried Nanopore Membranes with Enhanced Mechanical Robustness for High-Resolution Single-Molecule Sensing

Area of Science:

• Materials Science
• Nanotechnology
• Biophysics

Background:

• Ultrathin membranes in solid-state nanopores are mechanically fragile, hindering high-resolution single-molecule sensing.
• Current nanopore fabrication methods result in membranes susceptible to damage, limiting device performance and yield.

Purpose of the Study:

• To introduce a novel buried nanopore architecture to enhance the mechanical stability of ultrathin membranes.
• To improve the resolution and robustness of nanopore-based biosensing platforms.

Main Methods:

• Fabrication of recessed silicon nitride (SiN_x) membranes within a silicon substrate using controlled anisotropic wet etching.
• Characterization of membrane impact resistance and electrical conductance properties.
• Demonstration of sensing capabilities using double-stranded DNA translocation measurements.

Main Results:

• The buried nanopore architecture achieved over a tenfold increase in impact resistance compared to conventional surface membranes.
• Reduced effective membrane thickness was observed, indicating enhanced ionic confinement and spatial resolution.
• Successful label-free detection of short double-stranded DNA molecules (22 base pairs) was achieved, confirming high signal resolution.

Conclusions:

• The buried nanopore design significantly enhances mechanical durability and measurement resolution for nanopore biosensors.
• This scalable fabrication method offers a promising route for developing robust, high-performance single-molecule analysis devices.
• The improved device yield and stability pave the way for broader applications in molecular diagnostics and research.