COLL 398 |
| A real-time, label-free and electrical detection of biological interaction is a core issue for early detection of disease as well as personalized healthcare programs. Electronic devices composed of quantum structures, such as carbon nanotubes, semiconductor nanowires or quantum crystals have great potential for these applications. Recently, FET devices with carbon nanotube or Si nanowire as active channels have been demonstrated as a biosensor for detection of protein-protein interactions. Such devices, especially carbon nanotube FETs have been suffered from low sensitivity (~ 10 to 100 nM). In this presentation, we show successful fabrication of highly sensitive single walled carbon nanotube-FET (SWNT-FET) devices as they reproducibly detect nonspecific protein adsorptions and specific protein-protein interactions at 1 pM concentrations. The detection limit has been improved 104-fold compared to the devices fabricated by conventional photolithography. The substantially increased sensitivity is mainly due to the increased Schottky contact area which accommodates relatively more numbers of proteins even at very low concentration. The augmented number of proteins adsorbed on a device induces instant modulation of the work function of metal contact electrodes, which eventually changes the conductance of the device. Such devices have been attained by addressing metal electrodes on network-type CVD grown SWNTs using a shadow mask on a tilted angle sample stage. The shadow mask allows metals to penetrate underneath the mask efficiently, therefore forming a thin and wide Schottky contact area on SWNT channels. |
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Advances in Nanomedicine
8:30 AM-12:00 PM, Tuesday, 12 September 2006 Sir Francis Drake -- Monterey/Cypress Rooms, Oral
Division of Colloid & Surface Chemistry |