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Fine-tuning the Size and Minimizing the Noise of Solid-state Nanopores
Published on: October 31, 2013
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Low-Noise Solid-State Nanopore Enhancing Direct Label-Free Analysis for Small Dimensional Assemblies Induced by
Ruiping Wu1,2, Yesheng Wang1,2, Zhentong Zhu3
1State Key Lab of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China.
ACS Applied Materials & Interfaces
|January 21, 2021
Summary
Solid-state nanopores can now detect small molecules like cocaine and their assemblies. Introducing formamide into conical glass nanopores (CGNs) enhances resolution for single-molecule analysis, improving detection of molecular changes.
Area of Science:
- Nanotechnology
- Biophysics
- Analytical Chemistry
Background:
- Solid-state nanopores offer potential for single-molecule characterization but struggle with low resolution for small species.
- Existing methods lack the resolution to directly identify small-dimensional assemblies or subtle molecular changes.
- High-dielectric additives were previously shown to reduce noise and enhance resolution in conical glass nanopores (CGNs).
Purpose of the Study:
- To apply a bare CGN with a noise-reduction mechanism for direct recognition of small-dimensional assemblies induced by small molecules.
- To demonstrate the enhanced resolution of low-noise CGNs for detecting small conformational/size changes on larger substrates.
- To validate the improved capabilities of CGNs for sensitive molecular analysis at finer scales.
Main Methods:
- Utilizing a bare conical glass nanopore (CGN) with a high-dielectric additive (20% formamide) in the test buffer.
- Employing cocaine and its split aptamer (Capt assembly) as model systems for direct recognition.
- Using hybridization chain reaction (HCR) generated long duplex concatamers with aptamer side chains as model substrates for conformational change detection.
Main Results:
- High cocaine-specific distinguishing of the 113-nucleotide Capt assembly was achieved without labeling.
- Signal-to-background discrimination was significantly enhanced compared to gel electrophoresis and fluorescence resonance energy transfer (FRET).
- Low-noise CGN sensitively captured current changes indicating aptamer assembly on HCR duplexes in the presence of cocaine.
Conclusions:
- The introduction of a low-noise mechanism significantly improves the resolution of solid-state nanopores for small-scale analysis.
- Bare CGNs with formamide additives enable direct, label-free recognition of small molecular assemblies.
- This advancement opens avenues for extensive research in CGN-based single-molecular and statistical analysis, including molecular recognition and structure identification.
