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Updated: Sep 6, 2025
Fine-tuning the Size and Minimizing the Noise of Solid-state Nanopores
Published on: October 31, 2013
High Spatial Resolution of Ultrathin Covalent Organic Framework Nanopores for Single-Molecule DNA Sensing
Xiao-Lei Xing1, Zi-Chuan He1, Saud Asif Ahmed1
1State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Abstract:
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)6 showed the slowest transport speed (∼595 μs/base) compared with cytosine (∼355 μs/base) in poly(dC)6 and thymine (∼220 μs/base) in poly(dT)6. Such translocation speeds are the slowest ever reported in two-dimensional material-based nanopores. Poly(dA)6 also showed the biggest current blockade (94.74 pA) compared with poly(dC)6 (79.54 pA) and poly(dT)6 (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.
