Hyang-Sook Chun

Patterning of hierarchically aligned single-walled carbon nanotube Langmuir-Blodgett films by microcontact printing.

We present a patterning method for hierarchically aligned assembly of single-walled carbon nanotubes (SWNTs) using a combination of the Langmuir-Blodgett (LB) technique and soft lithography. The LB technique allows one to control the alignment and the surface density of SWNTs by adjusting surface pressure of the film at the air-water interface. The aligned SWNT Langmuir films are successfully transferred onto the polydimethylsiloxane (PDMS) or silicon substrate with unidirectional alignment, and SWNT patterns with various shapes are fabricated on silicon and flexible poly(ethylene terephthalate) (PET) substrates by contacting and peeling off the PDMS stamp from the substrates via microcontact printing or lift-up methods. The SWNT patterning technique using the combination of soft lithography and the LB method can be applied in various fields, such as flexible high-speed transistors, high-efficiency solar cells, and transparent electrodes.

Detection of deoxynivalenol using a MOSFET-based biosensor

We have detected deoxynivalenol(DON) using a metal-oxide-semiconductor field-effect-transistor(MOSFET)-based biosensor. The MOSFET-based biosensor is fabricated by a standard complementary metal-oxide-semiconductor(CMOS) process, and the biosensor`s electrical characteristics were investigated. The output of the sensor was stabilized by employing a reference electrode that applies a fixed bias to the gate. Au which has a chemical affinity for thiol was used as the gate metal to immobilize a self-assembled monolayer(SAM) made of 16-mercaptohexadecanoic acid(MHDA). The SAM was used to immobilize anti-deoxynivalenol antibody. The carboxyl group of the SAM was bound to the anti- deoxynivalenol antibody. Anti-deoxynivalenol antibody and deoxynivalenol were bound by an antigen-antibody reaction. In this study, it is confirmed that the MOSFET-based biosensor can detect deoxynivalenol at concentrations as low as 0.1 /ml. The measurements were performed in phosphate buffered saline(PBS; pH 7.4) solution. To verify the interaction among the SAM, antibody, and antigen, surface plasmon resonance(SPR) measurements were performed.

Fabrication of the CNT-FET biosensors with a double-gate structure

In this paper, we present the carbon nanotube field-effect transistor(CNT-FET) with a double-gate structure. A Carbon nanotube film was aligned by the Langmuir-Blodgett technique and was deposited to protect from water, oxygen, and other contaminants. We measured the electrical characteristics of the proposed device as the function of the , . From this result, we can confirm that proposed device might be employed as a biosensor.