In-plane Extended Nano-coulter Counter (XnCC) for the Label-free Electrical Detection of Biological Particles

Area of Science:

• Biotechnology
• Nanotechnology
• Microfluidics

Background:

• Nanopore sensors offer high sensitivity for particle detection.
• Existing fabrication methods can be complex and costly.
• A need exists for robust, scalable nanopore sensor fabrication.

Purpose of the Study:

• To fabricate an in-plane extended nanopore Coulter counter (XnCC) chip using thermoplastic imprinting.
• To demonstrate the utility of the XnCC chip for enumerating biological particles.

Main Methods:

• Fabricated microfluidic networks and nanopore sensors in silicon using photolithography and focused ion beam milling.
• Generated UV resin stamps from silicon masters.
• Utilized thermal imprinting to create the final XnCC chip in cyclic olefin polymer (COP).
• Enumerated SARS-CoV-2 viral particles (VPs) from saliva and extracellular vesicles (EVs) from plasma using the XnCC chip.

Main Results:

• Successfully fabricated an in-plane extended nanopore Coulter counter chip in COP via imprinting.
• Demonstrated enumeration of affinity-selected SARS-CoV-2 VPs from saliva.
• Showcased enumeration of affinity-selected EVs from plasma of irradiated mice.

Conclusions:

• The developed XnCC chip provides a scalable and effective platform for particle enumeration.
• This technology has potential applications in diagnostics and biological research.
• The XnCC chip enables sensitive detection of viral particles and extracellular vesicles.