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Updated: Oct 26, 2025
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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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Effect of single nanoparticle-nanopore interaction strength on ionic current modulation
Sohini Pal1, B Ramkumar1, Sanket Jugade1
1Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India.
Sensors and Actuators. B, Chemical
|July 29, 2021
Summary
Solid-state nanopore sensors show dwell time is exponentially sensitive to target-pore interactions. This sensitivity, driven by electrostatic forces, can enhance single molecule sensing applications.
Area of Science:
- Nanotechnology
- Biophysics
- Materials Science
Background:
- Solid-state nanopores are key for single molecule sensing.
- Ionic current modulation during molecule translocation is the primary measurement method.
- Dwell time, the molecule transit duration, is crucial for analysis.
Purpose of the Study:
- To investigate the relationship between target-pore interaction strength and dwell time in nanopore sensors.
- To explore electrostatic interactions using gold nanoparticles (NPs) and silicon nitride (SiN) nanopores.
- To demonstrate an operating regime where dwell time is highly sensitive to interaction strength.
Main Methods:
- Utilized single gold nanoparticles (NPs) as targets and a silicon nitride (SiN) nanopore sensor.
- Controlled electrostatic interaction strength by coating NPs with charged polymers.
- Measured dwell times for negatively and positively charged NPs interacting with a negatively charged SiN pore.
Main Results:
- Dwell time exhibits exponential sensitivity to the electrostatic interaction strength between NPs and the SiN nanopore.
- Positively charged NPs, experiencing strong attractive forces, showed a 2-3 order of magnitude increase in dwell times (0.4 ms to 75.3 ms).
- This highlights the significant impact of electrostatic forces on NP translocation dynamics.
Conclusions:
- The dwell time in nanopore sensors is highly sensitive to the strength of target-pore interactions, particularly attractive electrostatic forces.
- This extreme sensitivity can be leveraged to improve the performance and capabilities of emerging nanopore sensor applications.
- Nanopore sensors offer a powerful platform for precise single molecule analysis through controlled interactions.
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