Breaking the Size Barrier in Glass Nanopores to 2 nm: A Path to High-Resolution Biomolecular Fingerprinting

Glass nanopores have emerged as a promising single-molecule sensing platform due to their low intrinsic noise, facile fabrication, and excellent integrability. The fabrication of glass nanopores with diameters down to 1-3 nm, a scale comparable to nucleic acids and peptides, is a critical step toward high-resolution fingerprinting or event sequencing of these molecules, yet it remains a significant challenge. Here, it has overcome this obstacle by direct fabrication of ~2 nm glass nanopores, exemplified by the detection of double-stranded DNA (dsDNA) with an exceptional signal-to-noise ratio (SNR), exhibiting over 80% ionic current blockade. Furthermore, we demonstrate the discrimination of dsDNA as short as 40 base pairs (bp), the differentiation of single-stranded DNA (ssDNA) homopolymers (40 nucleotides). Finally, it is further highlighted that remarkably superior resolution successfully detects a DNA topological structure containing a 40-nucleotide (nt) gap within dsDNA, a feature that is extremely challenging to resolve using larger-diameter glass nanopores. This work marks a milestone in glass nanopores and paves the way for high-resolution biomolecular sensing, fingerprinting, and even sequencing.