State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
School of Pharmaceutical and Materials Engineering, Taizhou University, Taizhou 317000, China.
Anal Chem. 2022 Jul 12;94(27):9851-9855. doi: 10.1021/acs.analchem.2c01708. Epub 2022 Jun 25.
Ultrathin nanosheets of two-dimensional covalent organic frameworks covered a quartz nanopipette and then acted as a nanopore device for single-molecule DNA sensing. Our results showed that a single DNA homopolymer as short as 6 bases could be detected. The dwell times of 30-mer DNA homopolymers were obviously longer than the times of 10- or 6-mer ones. For different bases, poly(dA) showed the slowest transport speed (∼595 μs/base) compared with cytosine (∼355 μs/base) in poly(dC) and thymine (∼220 μs/base) in poly(dT). Such translocation speeds are the slowest ever reported in two-dimensional material-based nanopores. Poly(dA) also showed the biggest current blockade (94.74 pA) compared with poly(dC) (79.54 pA) and poly(dT) (71.41 pA). However, the present difference in blockade current was not big enough to distinguish the four DNA bases. Our study exhibits the shortest single DNA molecules that can be detected by COF nanopores at the present stage and lights the way for DNA sequencing based on solid-state nanopores.
二维共价有机框架的超薄纳米片覆盖在石英纳米管上，然后作为纳米孔器件用于单分子 DNA 传感。我们的结果表明，即使是短至 6 个碱基的单链 DNA 也可以被检测到。30 个碱基的 DNA 均聚物的停留时间明显长于 10 个碱基或 6 个碱基的均聚物。对于不同的碱基，与胞嘧啶（poly(dC)中为 355μs/碱基）和胸腺嘧啶（poly(dT)中为 220μs/碱基）相比，poly(dA)显示出最慢的传输速度（约 595μs/碱基）。这种传输速度是二维材料纳米孔中报道的最慢速度。与 poly(dC)（79.54pA）和 poly(dT)（71.41pA）相比，poly(dA)还显示出最大的电流阻断（94.74pA）。然而，目前的阻断电流差异还不足以区分四种 DNA 碱基。本研究展示了在现阶段可以通过 COF 纳米孔检测到的最短单链 DNA 分子，为基于固态纳米孔的 DNA 测序铺平了道路。
