The detection of oligosaccharides at the single-molecule level was investigated using a protein nanopore device. Neutral oligosaccharides of various molecular weights were translocated through a single alpha-hemolysin nanopore and their nano-transit recorded at the single-molecule level. The translocation of maltose and dextran oligosaccharides featured by 1 -> 4 and 1 -> 6 glycosidic bonds respectively was studied in an attempt to discriminate oligosaccharides according to their polymerization degree and glycosidic linkages. Oligosaccharides were translocated through a free diffusion regime indicating that they adopted an extended conformation during their translocation in the nanopore. The dwell time increased with molecular mass, suggesting the usefulness of nanopore as a molecular sizing device. (C) 2011 Elsevier Inc. All rights reserved.