title: Single-molecule DNA digestion in various alkanethiol-functionalized gold nanopores.
abstract: This paper presents the alkanethiol-functionalized environmental effects of individual DNA molecules in nanopores on enzyme digestion at the single-molecule level. A template consisting of gold deposited within a solid-state nanoporous polycarbonate membrane was used to trap individual λ-DNA and enzyme molecules. The gold surfaces were modified with various functional groups (-OH, -COOH, -NH3). The enzyme digestion rates of single DNA molecules increased with decreasing nanopore diameters. Surprisingly, the digestion rates in the l-cysteine chemisorbed nanopores were 2.1-2.6 times faster than in the mercaptoethanol chemisorbed gold nanopores, even though these nanopores had equivalent interspacial areas. In addition, the membrane of chemisorbed cysteamine with ionized functional groups of H3N(+) at pH 8.2 had a greater positive influence on the enzyme digestion rate than the membrane of chemisorbed mercaptoproponic acid with ionized carboxyl groups (COO(-)). These results suggest that the three-dimensional environment effect is strongly correlated with the functional group in confined nanopores and can significantly change the enzyme digestion rates for nanopores with different internal areas.
authors.affiliation: Department of Applied Chemistry, College of Applied Science, Kyung Hee University, Yongin-si, Gyeonggi-do 446-701, Republic of Korea.
authors.forename: Seungah
authors.initials: S
authors.lastname: Lee
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Kang
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D010582:Bacteriophage lambda / Q000378:metabolism*; D003545:Cysteine / Q000737:chemistry; D004279:DNA, Viral / Q000378:metabolism*; D004867:Equipment Design; D005092:Exonucleases / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D008567:Membranes, Artificial; D008623:Mercaptoethanol / Q000737:chemistry; D058608:Nanopores / Q000648:ultrastructure*; D061848:Optical Imaging; D011076:Polycarboxylate Cement / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000473:Alkanes; D004279:DNA, Viral; D008567:Membranes, Artificial; D011076:Polycarboxylate Cement; D013438:Sulfhydryl Compounds; C005506:polycarbonate; D008623:Mercaptoethanol; D006046:Gold; D005092:Exonucleases; D003545:Cysteine