RESUMO
The outstanding sensitivity of solid-state nanopore sensors comes at a price of low detection efficiency due to the lack of active means to transfer objects into the nanoscale sensing zone. Here we report on a key technology for high-throughput single-nanoparticle detection which exploits mutual effects of microfluidics control and multipore electrophoresis in nanopore-in-channel units integrated on a thin Si3N4 membrane. Using this novel nanostructure, we demonstrated a proof-of-concept for influenza viruses via hydropressure regulation of mass transport in the fluidic channel for continuous feeding of biosamples into the effective electric field extending out from the nanopores, wherein the feed-through mechanism allowed us to selectively detect charged objects in physiological media such as human saliva. With the versatility of nanopore sensing technologies applicable to analytes of virtually any size from cells to polynucleotides, the present integration strategy may open new avenues for practical ultrasensitive bioanalytical tools.
RESUMO
Solid-state micro- and nanopores are a versatile sensor platform capable of detecting single particles in electrolyte solution by cross-pore ionic current. Here we report on a use of this technology to identify airborne particulate matter. The detection concept lies in an electrophoretic control of air-floating particles captured in liquid to deliver them into a pore detector via microfluidic channels. We demonstrate resistive pulse measurements to machine-learning-based discriminations of intragranular contents of cypress and cedar pollens at a single-particle level. This all-electrical-sensor technique would pave a new venue toward real-time monitoring of single particles and molecules in air.
