title: Nanogap biosensors for electrical and label-free detection of biomolecular interactions.
abstract: 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.
authors.affiliation: BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, PO Box 115, Yuseong, Daejeon 305-600, Republic of Korea.
authors.forename: Sang
authors.initials: S
authors.lastname: Kyu Kim
authors.forename: Hyunmin
authors.initials: H
authors.lastname: Cho
authors.forename: Hye-Jung
authors.initials: HJ
authors.lastname: Park
authors.forename: Dohyoung
authors.initials: D
authors.lastname: Kwon
authors.forename: Jeong
authors.initials: J
authors.lastname: Min Lee
authors.forename: Bong
authors.initials: B
authors.lastname: Hyun Chung
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods*