title: Silicon nanoribbons for electrical detection of biomolecules.
abstract: Direct electrical detection of biomolecules at high sensitivity has recently been demonstrated using semiconductor nanowires. Here we demonstrate that semiconductor nanoribbons, in this case, a thin sheet of silicon on an oxidized silicon substrate, can approach the same sensitivity extending below the picomolar concentration regime in the biotin/streptavidin case. This corresponds to less than approximately 20 analyte molecules bound to receptors on the nanoribbon surface. The micrometer-size lateral dimensions of the nanoribbon enable optical lithography to be used, resulting in a simple and high-yield fabrication process. Electrical characterization of the nanoribbons is complemented by computer simulations showing enhanced sensitivity for thin ribbons. Finally, we demonstrate that the device can be operated both in inversion as well as in accumulation mode and the measured differences in detection sensitivity are explained in terms of the distance between the channel and the receptor coated surface with respect to the Debye screening length. The nanoribbon approach opens up for large scale CMOS fabrication of highly sensitive biomolecule sensor chips for potential use in medicine and biotechnology.
authors.affiliation: Department of Microelectronics and Applied Physics, Royal Institute of Technology, SE-164 40 Stockholm, Sweden. niklasel@kth.se
authors.forename: Niklas
authors.initials: N
authors.lastname: Elfström
authors.forename: Amelie Eriksson
authors.initials: AE
authors.lastname: Karlström
authors.forename: Jan
authors.initials: J
authors.lastname: Linnros
mesh_terms: D001710:Biotin / Q000032:analysis* / Q000737:chemistry*; D004563:Electrochemistry; D004583:Electrons; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D012825:Silicon / Q000737:chemistry*; D012996:Solutions; D019809:Streptavidin / Q000032:analysis* / Q000737:chemistry*
chemical_list: D012996:Solutions; D001710:Biotin; D019809:Streptavidin; D012825:Silicon