title: Thin film polycrystalline silicon nanowire biosensors.
abstract: Polysilicon nanowire biosensors have been fabricated using a top-down process and were used to determine the binding constant of two inflammatory biomarkers. A very low cost nanofabrication process was developed, based on simple and mature photolithography, thin film technology, and plasma etching, enabling an easy route to mass manufacture. Antibody-functionalized nanowire sensors were used to detect the proteins interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) over a wide range of concentrations, demonstrating excellent sensitivity and selectivity, exemplified by a detection sensitivity of 10 fM in the presence of a 100,000-fold excess of a nontarget protein. Nanowire titration curves gave antibody-antigen dissociation constants in good agreement with low-salt enzyme-linked immunosorbent assays (ELISAs). This fabrication process produces high-quality nanowires that are suitable for low-cost mass production, providing a realistic route to the realization of disposable nanoelectronic point-of-care (PoC) devices.
authors.affiliation: School of Electronics & Computer Science, University of Southampton, Southampton, SO17 1BJ, UK. mmah@ecs.soton.ac.uk
authors.forename: Mohammad M A
authors.initials: MM
authors.lastname: Hakim
authors.forename: Marta
authors.initials: M
authors.lastname: Lombardini
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.forename: Francesco
authors.initials: F
authors.lastname: Giustiniano
authors.forename: Peter L
authors.initials: PL
authors.lastname: Roach
authors.forename: Donna E
authors.initials: DE
authors.lastname: Davies
authors.forename: Peter H
authors.initials: PH
authors.lastname: Howarth
authors.forename: Maurits R R
authors.initials: MR
authors.lastname: de Planque
authors.forename: Hywel
authors.initials: H
authors.lastname: Morgan
authors.forename: Peter
authors.initials: P
authors.lastname: Ashburn
mesh_terms: D000937:Antigen-Antibody Reactions; D015415:Biomarkers / Q000032:analysis; D015374:Biosensing Techniques / Q000295:instrumentation*; D003460:Crystallization; D004797:Enzyme-Linked Immunosorbent Assay; D007249:Inflammation; D016209:Interleukin-8 / Q000032:analysis / Q000276:immunology; D008567:Membranes, Artificial; D053770:Nanowires / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000276:immunology
chemical_list: D015415:Biomarkers; D016209:Interleukin-8; D008567:Membranes, Artificial; D011108:Polymers; D014409:Tumor Necrosis Factor-alpha; D012825:Silicon