Abstract: Methods and apparatus for evanescent light fluoroimmunoassays are disclosed. The apparatus employs a planar waveguide with an integral semicylindrical lens, and has multi-analyte features and calibration features, along with improved evanescent field intensity. A preferred embodiment of the biosensor and assay method has patches of capture molecules, each specific for a different analyte disposed adjacently within a single reservoir. The capture molecules are immobilized to the patches on the waveguide surface by site-specific coupling of thiol groups on the capture molecules to photo-affinity crosslinkers, which in turn are coupled to the waveguide surface or to a nonspecific binding-resistant coating on the surface. The patches of different antibodies are produced by selectively irradiating a portion of the waveguide surface during the process of coupling the photo-affinity crosslinkers, the selective irradiation involving a mask, a laser light source, or the like.
Type:
Grant
Filed:
November 13, 2001
Date of Patent:
December 27, 2005
Assignee:
BioCentrex, LLC
Inventors:
James N. Herron, Douglas A. Christensen, Hsu-Kun Wang, Karin Caldwell, Vera Janatová, Shao-Chie Huang
Abstract: A step-gradient composite waveguide for evanescent sensing in fluorescent binding assays comprises a thick substrate layer having one or more thin film waveguide channels deposited thereon. In one embodiment, the substrate is silicon dioxide and the thin film is silicon oxynitride. Specific binding molecules having the property of binding with specificity to an analyte are immobilized on the surface of the thin film channels. In preferred embodiments, the composite waveguide further includes light input coupling means integrally adapted to the thin film channels. Such light coupling means can be a grating etched into the substrate prior to deposition of the thin film, or a waveguide coupler affixed to the upper surface of the thin film. The waveguide coupler has a thick input waveguide of high refractive index which receives the laser light through one end and propagates it by total internal reflection.
Type:
Grant
Filed:
November 3, 1998
Date of Patent:
June 28, 2005
Assignee:
BioCentrex, LLC
Inventors:
W. Monty Reichert, James N. Herron, Douglas A. Christensen, Hsu-Kun Wang, Jacob D. Durtschi