title: An evanescent fluorescence biosensor using ion-exchanged buried waveguides and the enhancement of peak fluorescence.
abstract: The principle of an optical molecular sensor using ion-exchanged buried planar waveguides in glass has been demonstrated. We have shown both theoretically and experimentally that the intensity of the peak evanescent fluorescence can be increased by several orders of magnitude with the use of an index-matching material. The method of differential measurement has been used to improve the differentiation between specific and non-specific binding. We used h-IgG (human immunoglobulin G) as the immobilized antibody on the surface of the waveguide and protein A-FITC (fluorescein isothiocyanate) as the fluorescently labelled antigen or anti-antibody to be detected, and have shown that a concentration of protein A as low as 24 nM can easily be detected.
authors.affiliation: Department of Electronics and Electrical Engineering, University of Glasgow, UK.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.forename: P J
authors.initials: PJ
authors.lastname: Laybourn
authors.forename: J V
authors.initials: JV
authors.lastname: Magill
authors.forename: R M
authors.initials: RM
authors.lastname: De La Rue
mesh_terms: D015374:Biosensing Techniques; D016650:Fluorescein-5-isothiocyanate; D015200:Fluoroimmunoassay; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007474:Ion Exchange; D008433:Mathematics; D008954:Models, Biological; D011188:Potassium / Q000737:chemistry; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D013205:Staphylococcal Protein A / Q000032:analysis
chemical_list: D007074:Immunoglobulin G; D013205:Staphylococcal Protein A; D016650:Fluorescein-5-isothiocyanate; D011188:Potassium