Nanogap biosensors for electrical and label-free detection of biomolecular interactions.
We demonstrate nanogap biosensors for electrical and label-free detection of biomolecular interactions. Parallel fabrication of nanometer distance gaps has been achieved using a silicon anisotropic wet etching technique on a silicon-on-insulator (SOI) wafer with a finely controllable silicon device layer. Since silicon anisotropic wet etching resulted in a trapezoid-shaped structure whose end became narrower during the etching, the nanogap structure was simply fabricated on the device layer of a SOI wafer. The nanogap devices were individually addressable and a gap size of less than 60 nm was obtained. We demonstrate that the nanogap biosensors can electrically detect biomolecular interactions such as biotin/streptavidin and antigen/antibody pairs. The nanogap devices show a current increase when the proteins are bound to the surface. The current increases proportionally depending upon the concentrations of the molecules in the range of 100 fg ml(-1)-100 ng ml(-1) at 1 V bias. It is expected that the nanogap developed here could be a highly sensitive biosensor platform for label-free detection of biomolecular interactions.
Kyu Kim
Sang
S
BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, PO Box 115, Yuseong, Daejeon 305-600, Republic of Korea.
Cho
Hyunmin
H
Park
Hye-Jung
HJ
Kwon
Dohyoung
D
Min Lee
Jeong
J
Hyun Chung
Bong
B
D015374:Biosensing Techniques / Q000379:methods*; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods*