Direct Chemical Detection in a Microchannel with a Nanoneedle-Based Biological Nanopore Probe

This paper describes the development of a spatially-resolved biological nanopore probe which pore-forming proteins are reconstituted in a bilayer lipid membrane (BLM) supported on a poly-ethylene glycol (PEG)-modified nanoneedle and the demonstration of chemical detection in an H-shaped microchannel with the probe. Recently, biological nanopore probes (BNPs) that can simultaneously measure chemical and topography information using the α-hemolysin (αHL) nanopore supported on a pulled-pipette probe were developed. Although BNPs have a potential to provide spatially-resolved imaging, the resolution is limited in comparison to state-of-the-art scanning probe microscopies because of the pipette size ( ~ 30μm O.D.). In this study, we developed a nanoneedle-based BNP which the PEG monolayer supports the BLM, the pore-forming membrane proteins are reconstituted on the tip of the nanoneedle. Furthermore, we demonstrated the detection of chemical in the microchannel using the nanoneedle-based BNP. We believe that our BNP has a potential as a living cell imaging system that can measure chemicals and topography with nanometer resolution.