title: Differentiation of short, single-stranded DNA homopolymers in solid-state nanopores.
abstract: In the last two decades, new techniques that monitor ionic current modulations as single molecules pass through a nanoscale pore have enabled numerous single-molecule studies. While biological nanopores have recently shown the ability to resolve single nucleotides within individual DNA molecules, similar developments with solid-state nanopores have lagged, due to challenges both in fabricating stable nanopores of similar dimensions as biological nanopores and in achieving sufficiently low-noise and high-bandwidth recordings. Here we show that small silicon nitride nanopores (0.8- to 2-nm diameter in 5- to 8-nm-thick membranes) can resolve differences between ionic current signals produced by short (30 base) ssDNA homopolymers (poly(dA), poly(dC), poly(dT)), when combined with measurement electronics that allow a signal-to-noise ratio of better than 10 to be achieved at 1-MHz bandwidth. While identifying intramolecular DNA sequences with silicon nitride nanopores will require further improvements in nanopore sensitivity and noise levels, homopolymer differentiation represents an important milestone in the development of solid-state nanopores.
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Venta
authors.forename: Gabriel
authors.initials: G
authors.lastname: Shemer
authors.forename: Matthew
authors.initials: M
authors.lastname: Puster
authors.forename: Julio A
authors.initials: JA
authors.lastname: Rodríguez-Manzo
authors.forename: Adrian
authors.initials: A
authors.lastname: Balan
authors.forename: Jacob K
authors.initials: JK
authors.lastname: Rosenstein
authors.forename: Ken
authors.initials: K
authors.lastname: Shepard
authors.forename: Marija
authors.initials: M
authors.lastname: Drndić
mesh_terms: D004277:DNA, Single-Stranded / Q000032:analysis* / Q000737:chemistry*; D008958:Models, Molecular; D058608:Nanopores; D009690:Nucleic Acid Conformation; D018272:Porins / Q000737:chemistry; D017655:Silicon Compounds / Q000737:chemistry
chemical_list: D004277:DNA, Single-Stranded; D018272:Porins; D017655:Silicon Compounds; C032734:silicon nitride