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

We report an in-plane extended nanopore Coulter counter (XnCC) chip fabricated in a thermoplastic via imprinting. The fabrication of the sensor utilized both photolithography and focused ion beam milling to make the microfluidic network and the in-plane pore sensor, respectively, in Si from which UV resin stamps were generated followed by thermal imprinting to produce the final device in the appropriate plastic (cyclic olefin polymer, COP). As an example of the utility of this in-plane extended nanopore sensor, we enumerated SARS-CoV-2 viral particles (VPs) affinity-selected from saliva and extracellular vesicles (EVs) affinity-selected from plasma samples secured from mouse models exposed to different ionizing radiation doses.

Automated summary

We present an in-plane extended nanopore Coulter counter (XnCC) chip fabricated using imprinting in a thermoplastic material. The sensor was made using photolithography and focused ion beam milling to create the microfluidic network and in-plane pore sensor, respectively, in Si. UV resin stamps were then generated and used for thermal imprinting to produce the final device in the desired plastic material (cyclic olefin polymer, COP). As a demonstration, we used this in-plane extended nanopore sensor to count SARS-CoV-2 viral particles (VPs) affinity-selected from saliva and extracellular vesicles (EVs) affinity-selected from plasma samples obtained from mouse models exposed to different ionizing radiation doses.