Immunosensing with photo-immobilized immunoreagents on planar optical wave guides

• Published in: Biosensors & bioelectronics Vol. 10; no. 3; pp. 317 - 328
• Main Authors: Gao, Hui, Sänger, Michael, Luginbühl, Reto, Sigrist, Hans
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 1995; Elsevier Science
• Subjects: antibody immobilization; Antigen-Antibody Reactions; Biological and medical sciences; Biosensing Techniques; Biosensors; Biotechnology; enzyme-linked immunoassay; Fundamental and applied biological sciences. Psychology; Immobilization of enzymes and other molecules; Immobilization techniques; immunochemical sensor; Immunoglobulins - analysis; integrated optics; Methods. Procedures. Technologies; photo-immobilization; Photochemistry; Space life sciences; titanium oxide/silicon oxide; Various methods and equipments; immunochemical sensor; titanium oxide/silicon oxide; enzyme-linked immunoassay; integrated optics; antibody immobilization; photo-immobilization; Bovine; Immobilization; Serum albumin; Monoclonal antibody; Photochemical reaction; Immunosensor; Surface; Vertebrata; Mammalia; Biosensor; Covalent bond; F(ab')2-Fragment; Optical waveguide; Artiodactyla; Titanium oxide; Ungulata
• DOI: 10.1016/0956-5663(95)96850-X
• ISSN: 0956-5663

Immunocomplexation at wave guiding TiO 2/SiO 2 surfaces was investigated using an integrated optical grating coupler. For extended application of this label-free monitoring system, F(ab′) 2 fragments of monoclonal antibodies were photo-immobilized by photolinker polymer-mediated procedures that do not require functionalization of either the immonoreagent or the TiO 2/SiO 2 surface. Covalent, light-dependent binding of photolinker polymer and F(ab′) 2 fragments was achieved using a single-step photo-reaction. Bovine serum albumin derivatized with aryldiazirines (T-BSA) served as a photolinker polymer. T-BSA suppressed the non-specific adsorption of analytes to wave guide surfaces. Immunoreagent binding and immunological activity were analyzed and modified surfaces were investigated by scanning force microscopy. Apparent immunoreagent surface densities were 16·7 fmol F(ab′) 2 per mm 2 sensor surface. Optical analyses revealed linear, dose-dependent antigen binding with label free analytes. Immunocompetent surfaces were regenerable by treatment at pH 2·3, rendering the immunosensing system applicable for repetitive use.