Step-defect guided delivery of DNA to a graphene nanopore

• Published in: Nature nanotechnology Vol. 14; no. 9; pp. 858 - 865
• Main Authors: Shankla, Manish, Aksimentiev, Aleksei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2019; Nature Publishing Group
• Subjects: 119/118; 631/61/350/1058; 639/301/1034/1035; 639/301/357/1018; Biomolecules; Chemical reactions; Chemistry and Materials Science; Defects; Deoxyribonucleic acid; Dependence; DNA; DNA - chemistry; Domains; Graphene; Graphite - chemistry; Hydrophobic and Hydrophilic Interactions; Materials Science; Molecular dynamics; Molecular Dynamics Simulation; Motion; Multilayers; Nanopores - ultrastructure; Nanotechnology; Nanotechnology and Microengineering; Organic chemistry; Porosity; Transport
• ISSN: 1748-3387; 1748-3395; 1748-3395
• DOI: 10.1038/s41565-019-0514-y

Precision placement and transport of biomolecules are critical to many single-molecule manipulation and detection methods. One such method is nanopore sequencing, in which the delivery of biomolecules towards a nanopore controls the method’s throughput. Using all-atom molecular dynamics, here we show that the precision transport of biomolecules can be realized by utilizing ubiquitous features of graphene surface-step defects that separate multilayer domains. Subject to an external force, we found that adsorbed DNA moved much faster down a step defect than up, and even faster along the defect edge, regardless of whether the motion was produced by a mechanical force or a solvent flow. We utilized this direction dependency to demonstrate a mechanical analogue of an electric diode and a system for delivering DNA molecules to a nanopore. The defect-guided delivery principle can be used for the separation, concentration and storage of scarce biomolecular species, on-demand chemical reactions and nanopore sensing. Subject to force, molecules are more likely to move down a step defect than up the defect and are even more likely to be displaced along the step defect line.