Simultaneous Ionic Current and Potential Detection of Nanoparticles by a Multifunctional Nanopipette

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Electrochemistry

Background:

• Nanopore sensing offers advanced single-molecule and nanoparticle analysis.
• Multifunctional nanopores enhance sensitivity and selectivity beyond traditional methods.

Purpose of the Study:

• To demonstrate cooperative label-free electric sensing modes for detecting gold nanoparticle motion.
• To utilize multifunctional nanopipettes for improved nanoparticle analysis.

Main Methods:

• Fabrication of multifunctional nanopipettes with integrated nanopores and nanoelectrodes (pyrolytic carbon).
• Simultaneous measurement of ionic current and local electrical potential during nanoparticle translocation.
• Utilizing nanopore/carbon nanoelectrode (CNE) tip geometry for dual sensing capabilities.

Main Results:

• Successful detection of 40 nm gold nanoparticle (GNP) motion using combined sensing modes.
• Distinguished between individual GNP translocation inside the nanopore and collective accumulation outside.
• Identified GNP accumulation near the nanopore entrance via potential changes, undetectable by current alone.

Conclusions:

• Cooperative sensing modes in multifunctional nanopipettes significantly enhance the detection and analysis of nanoparticles.
• The developed method allows for comprehensive monitoring of nanoparticle dynamics both within and external to the nanopore.
• This approach provides a powerful tool for studying nanoparticle behavior in solution.