Novel Nanofluidic Chemical Cells based on Self-Assembled Solid-State SiO2 Nanotubes
Hao Zhu, Haitao Li, Arvind K. Balijepalli, Joseph W. Robertson, Sergiy Krylyuk, Albert Davydov, John J. Kasianowicz, John S. Suehle, Qiliang Li
Novel nanofluidic chemical cells based on self-assembled solid-state SiO2 nanotubes on silicon- on-insulator (SOI) substrates have been successfully fabricated and tested. The vertical SiO2 nanotubes with a smooth cavity are built from Si nanowires which were epitaxially grown on the SOI surface. The nanotubes have a rigid, dry-oxidized SiO2 wall with precisely controlled nanotube inner diameter, very attractive for chemical-/bio-sensing applications. No dispersion/aligning procedures were involved in the fabrication of nanofluidic devices by using this technology, enabling clean and smooth chemical cell. Ion translocation measurements have been successfully carried out on a SiO2 nanotube channel with 20 nm in diameter. A robust and well-controlled nanotube chemical cell is an excellent case of developing functional nanomaterials by leveraging the strength of top-down lithography and the unique advantage of bottom-up growth. These solid, smooth, clean SiO2 nanotubes and nanofluidic devices are very encouraging and attractive in future bio-medical applications, such as single molecule sensing and DNA sequencing.