title: Characterisation of a label-free biosensor based on long period grating.
abstract: Optical fibre gratings, especially long period gratings, have been recently proposed as optical devices for biochemical sensing. A biochemical interaction along the grating portion induces a refractive index change and hence a change in the fiber transmission spectrum. This provides an alternative methodology with respect to other label-free optical approaches, such as surface plasmon resonance, interferometric configurations and optical resonators. The fibre biofunctionalization has been carried out by means of a novel chemistry using Eudragit L100 copolymer as opposed to the commonly used silanization procedure. Antigen-antibody interaction has been analysed by means of an IgG/anti-IgG bioassay. The biosensor was fully characterised, monitoring the kinetics during the antibody immobilization and the antigen interaction and achieving the calibration curve of the assay. A comparison of the biosensor performance was made by using two different long period gratings with distinct periods.
authors.affiliation: IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Chiavaioli
authors.forename: Cosimo
authors.initials: C
authors.lastname: Trono
authors.forename: Ambra
authors.initials: A
authors.lastname: Giannetti
authors.forename: Massimo
authors.initials: M
authors.lastname: Brenci
authors.forename: Francesco
authors.initials: F
authors.lastname: Baldini
mesh_terms: D000818:Animals; D055910:Antibodies, Immobilized / Q000032:analysis / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D005240:Feasibility Studies; D007074:Immunoglobulin G / Q000032:analysis / Q000737:chemistry; D051379:Mice; D055100:Optical Fibers
chemical_list: D055910:Antibodies, Immobilized; D007074:Immunoglobulin G
keywords: biochemical sensing; flow cell; immunoassay; label-free; long period grating