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Single Molecule DNA Analysis Based on Atomic-Controllable Nanopores in Covalent Organic Frameworks
Xiao-Lei Xing1, Qiao-Bo Liao1, Saud Asif Ahmed1
1State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Nano Letters
|January 26, 2022
Summary
Two-dimensional covalent organic frameworks (2D COFs) show promise for single DNA molecule analysis. These COF nanosheets function as nanopores, enabling slow DNA transport and size selectivity for future biosensing applications.
Area of Science:
- Materials Science
- Nanotechnology
- Biophysics
Background:
- Two-dimensional covalent organic frameworks (2D COFs) are emerging materials with tunable properties.
- Nanopores are crucial for single-molecule analysis, enabling the study of individual molecules like DNA.
- Existing nanopore technologies often rely on inorganic materials or biological channels.
Purpose of the Study:
- To investigate the potential of 2D COF nanosheets as nanopores for single DNA molecule analysis.
- To evaluate the size selectivity and transport characteristics of COF nanopores for DNA molecules.
- To compare the performance of COF nanopores with existing 2D nanomaterials.
Main Methods:
- Exfoliation of ultrathin 2D COF nanosheets with specific pore sizes (1.1 nm and 1.3 nm).
- Coating of COF nanosheets onto quartz nanopipettes with a 20 ± 5 nm orifice.
- Studying the transport of fluorescent dyes and DNA molecules (calf thymus DNA and DNA-80) through COF nanopores.
- Measuring the translocation speed of DNA molecules through the nanopores.
Main Results:
- COF nanopores demonstrated high size selectivity for both fluorescent dyes and DNA molecules.
- The translocation speed of DNA-80 through the COF-1.1 nanopore was measured at 270 μs/base, the slowest observed for 2D nanomaterials.
- Strong interactions between DNA bases and COF organic backbones were identified as the cause for slow translocation.
Conclusions:
- 2D COF nanosheets can function as individual nanopore monomers.
- The pore size of COF nanosheets is controllable, similar to biological nanopores.
- COF-based nanopores offer a promising platform for advanced single DNA molecule analysis with tunable properties.
