Electrical detection of the temperature induced melting transition of a DNA hairpin covalently attached to gold interdigitated microelectrodes.

The temperature induced melting transition of a self-complementary DNA strand covalently attached at the 5' end to the surface of a gold interdigitated microelectrode (GIME) was monitored in a novel, label-free, manner. The structural state of the hairpin was assessed by measuring four different electronic properties of the GIME (capacitance, impedance, dissipation factor and phase angle) as a function of temperature from 25 degrees C to 80 degrees C. Consistent changes in all four electronic properties of the GIME were observed over this temperature range, and attributed to the transition of the attached single-stranded DNA (ssDNA) from an intramolecular, folded hairpin structure to a melted ssDNA.

Current rectification in a single silicon nanowire p-n junction.

Diodes within individual silicon nanowires were fabricated by doping them during growth to produce p-n junctions. Electron beam lithography was then employed to contact p- and n-doped ends of these nanowires. The current-voltage (I-V) measurements showed diode-like characteristics with a typical threshold voltage (Vt) of about 1 V and an ideality factor (n) of about 3.

SiGe nanowire field effect transistors.

Si0.5Geo0.5 nanowires have been utilized to fabricate source-drain channels of p-type field effect transistors (p-FETs).