Network single-walled carbon nanotube-field effect transistors (SWNT-FETs) with increased Schottky contact area for highly sensitive biosensor applications.
Highly sensitive single-walled carbon nanotube-field effect transistor (SWNT-FET) devices, which detect protein adsorptions and specific protein-protein interactions at 1 pM concentrations, have been achieved. The detection limit has been improved 104-fold compared to the devices fabricated by 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 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.
Department of Chemistry, Pohang University of Science and Technology, San 31, Hyoja-Dong, Nam-Gu, Pohang, Korea 790-784.
Hye Ryung
HR
Byon
Hee Cheul
HC
Choi
D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000032:analysis / Q000737:chemistry; D007074:Immunoglobulin G / Q000032:analysis / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013205:Staphylococcal Protein A / Q000737:chemistry; D014173:Transistors, Electronic
D018997:Chorionic Gonadotropin, beta Subunit, Human; D007074:Immunoglobulin G; D037742:Nanotubes, Carbon; D013205:Staphylococcal Protein A