Single Molecule DNA Analysis Based on Atomic-Controllable Nanopores in Covalent Organic Frameworks

• Published in: Nano letters Vol. 22; no. 3; pp. 1358 - 1365
• Main Authors: Xing, Xiao-Lei, Liao, Qiao-Bo, Ahmed, Saud Asif, Wang, Dongni, Ren, Shibin, Qin, Xiang, Ding, Xin-Lei, Xi, Kai, Ji, Li-Na, Wang, Kang, Xia, Xing-Hua
• Format: Journal Article
• Language: English
• Published: United States 09.02.2022
• Subjects: DNA; Fluorescent Dyes; Metal-Organic Frameworks; Nanopores; DNA translocation; Covalent organic frameworks (COFs); single molecule analysis; size selectivity; atomic-controllable nanopore
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.1c04633

We explored the application of two-dimensional covalent organic frameworks (2D COFs) in single molecule DNA analysis. Two ultrathin COF nanosheets were exfoliated with pore sizes of 1.1 nm (COF-1.1) and 1.3 nm (COF-1.3) and covered closely on a quartz nanopipette with an orifice of 20 ± 5 nm. COF nanopores exhibited high size selectivity for fluorescent dyes and DNA molecules. The transport of long (calf thymus DNA) and short (DNA-80) DNA molecules through the COF nanopores was studied. Because of the strong interaction between DNA bases and the organic backbones of COFs, the DNA-80 was transported through the COF-1.1 nanopore at a speed of 270 μs/base, which is the slowest speed ever observed compared with 2D inorganic nanomaterials. This study shows that the COF nanosheet can work individually as a nanopore monomer with controllable pore size like its biological counterparts.