We used helium ion microscope to reduce the pore size of a nanoporous membrane with a resolution of less than 1 nm (DOI: 10.1038/s41467-018-03316-7 , Open Access).
The same method was applied to produce extremely thin nanowires with high precision and control over the dimensions (DOI: 10.1002/pssr.201700333 , Open Access).
Both nanoporous membranes and nanowires studied, are of great interest as biosensing platform. Therefore it is expected that the reported results will make a big impact in the field, enabling the researchers to further investigate and optimize the introduced method for more practical application.
Moreover, we used the same technique to produce nanoholes (< 10 nm in size with <1 nm resolution) on top of a cantilever which is then mounted on an Atomic Force Microscope (AFM). The probe acts as a nanopore sensors and it allows localized detection of ions and biomolecules. For example, the force feedback of the AFM enables precise localization of the cantilever inside of a living cell or a tissue. The nanopore sensors records translocation of the biomolecules which appear as a transient jump in the current signal. The shape and the length of the transient signal provides information regarding the type and length of the translocating molecules. This platform is used for molecular level sensing inside and outside of a live cell and the new technology is called scanning nanopore microscope. (the results of this work will be published in the future)
In a parallel study, we characterized the physical properties of the scanning nanopore microscope and found out its potentials and limitations in studying nano-structured surfaces. This detailed study shows that the size and shape of the fabricated pores are of great importance in the functionality of the device (the results will be published online in Journal of Applied Physics 2018).
