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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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Beyond nanopore sizing: improving solid-state single-molecule sensing performance, lifetime, and analyte scope for
Y M Nuwan D Y Bandara1, Jugal Saharia1, Buddini I Karawdeniya1
1Department of Mechanical Engineering, Southern Methodist University, Dallas, TX 75275, United States of America.
Nanotechnology
|May 2, 2020
Summary
We developed a novel fabrication method for solid-state nanopores (SSNs) that significantly improves their stability and analyte sensing capabilities for DNA, proteins, and glycans.
Area of Science:
- Nanotechnology
- Biophysics
- Materials Science
Background:
- Solid-state nanopores (SSNs) offer single-molecule resolution for bio-polymer analysis, including DNA sequencing.
- Controlled dielectric breakdown (CDB) enhanced SSN accessibility but introduced challenges like current drift and analyte sticking.
- These issues hinder research and commercialization, especially with diverse analytes.
Purpose of the Study:
- To develop an improved SSN fabrication method addressing current drift and analyte sticking.
- To create robust SSNs capable of sensing a broad range of analytes.
- To investigate the impact of nanopore surface chemistry on sensor performance.
Main Methods:
- Modified the controlled dielectric breakdown (CDB) fabrication process using a chemical additive (sodium hypochlorite).
- Fabricated silicon nitride (SiNx) nanopores with controlled surface chemistry.
- Characterized nanopore performance, including current stability, analyte translocation, and responsiveness.
Main Results:
- Achieved Ohmic nanopore behavior in electrolyte with stable open-pore current (>1 hour) for pores ranging from 3-30 nm.
- Demonstrated spontaneous current correction during analyte translocation.
- Observed significantly improved responsiveness to negatively charged analytes like DNA (approx. 6.5x increase).
- Reduced surface group acidity (Ka) by ~3 orders of magnitude compared to standard CDB pores.
Conclusions:
- The novel SSN fabrication method significantly enhances sensor stability and performance.
- Tailoring nanopore surface chemistry is crucial for overcoming limitations in bio-polymer sensing.
- These improved SSNs are suitable for diverse real-time bio-polymer profiling applications.
