The sensitive and robust detection of harmful biological and chemical molecules in the various samples have incredible significance in modern healthcare. New research in the field of nanowires has evidence that nanowire based diagnostic methods may be the next great leap in clinical tools. We have designed and fabricated various nano field effect transistors (FET) containing low doped polysilicon nanowires (30nm -500nm) on silicon wafers to optimize the best feature size and stable output. The nano-FET’s were characterized by electrochemical impedance spectroscopy in various modes. Obtained spectra were fitted with proposed equivalent circuit model to calculate various electrical parameters. The nano-FET electrode surfaces were functionalized with the PNA and DNA molecular capture system. When targeted DNA or bio-agents were captured the constant overall impedance increased or decreased depending on the charge on target molecule. Our device records very small signal changes on the electrode surface indicates the strong influence of the capacitance changes as a result of DNA binding. We have also improved the efficiency and strength of various targeted proteins, PNA and DNA binding to the surface by our developed covalent binding method. Current data indicates that our nano-FET will be the basis for a robust hand held tool for bio-threat and clinical detection.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2007 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: May 20, 2007
Pages: 465 - 468
Industry sector: Sensors, MEMS, Electronics
Topics: Biomaterials, Chemical, Physical & Bio-Sensors