Single-molecule glycan discrimination using a graphite nanopore.

Glycans are fundamental biomolecules whose biological functions are encoded in subtle structural features, posing significant challenges for their analytical discrimination. In this all-atom molecular dynamics study, we demonstrate that a negatively charged graphite nanopore enables accurate single-molecule glycan detection. Glycans differing in N-acetylation number, N-acetylation pattern, and regioisomeric structure are reliably discriminated. In fact, from a mechanistic perspective, distinct ionic current signatures are traced back to species-specific spatial charge accumulation around individual glycans confined within the nanopore lumen. Moreover, under applied transmembrane voltage, the negatively charged nanopore generates electroosmotic flow, which drives glycan translocation and offers a chemically label-free approach for glycan detection.