SnO2 nanowire bio-transistor for electrical DNA sensing
Authors: Baratto C., Todros S., Comini E., Faglia G., Ferroni M., Sberveglieri G., Marrazza G., Andreano G., Cellai L., Flamini A., Nannini A., Pennelli G., Piotto M.
Autors Affiliation: Department of Chemistry and Physics, CNR-INFM, University of Brescia, Brescia, Italy; Department of Chemistry, University of Florence, Florence, Italy; Institute of Crystallography, Institute of Structure of Matter, CNR, Rome, Italy; Department of Information Engineering, University of Pisa, IEIIT CNR, Pisa, Italy
Abstract: An innovative JFET bio-transistor, based on a metal oxide (MOX) nanowire bundle, was developed in order to electrically detect biological binding. The working principle of this device relies on modulation of a MOX space charge region (SCR), acting as the channel of a field effect transistor, instead of an enriched/depleted Si channel like in chem.-FETs. The feasibility was at first demonstrated by the development of a bio-sensor made of an SnO2 thin film derivatized with oligodeoxyribonucleotide-probes. We implemented a protocol to immobilize single strands of nucleic acid over SnO2 and developed a system for electrical sensing of hybridization in liquid solution. The same protocol was then applied on a SnO2 nanowire bundle, synthesized by thermal evaporation of oxide powders under controlled conditions with the presence of Pt catalyst. The results obtained on a group of nanowires suggest the possibility – now under development – to produce nano-bio-transistors based on single nanowires of metal oxides.
KeyWords: Electric wire; Field effect transistors; Metallic compounds; Metals; Modulation; Silicon, Biological binding; Metal oxides; Nano wires; Space-charge region; Working principles, SensorsDOI: 10.1109/ICSENS.2007.4388606