Optical biosensor assay (OBA).
We describe a new biosensor immunoassay involving optical diffraction to detect clinically important analytes in human body fluids. A silicon wafer is used as a support for immobilization of antigen or antibody. The protein-coated surface is illuminated through a photo mask to create distinct periodic areas of active and inactive protein. When the surface is incubated with a positive sample, antigen-antibody binding occurs only on the active areas. Upon illumination with a light source such as a laser, the resulting biological diffraction grating diffracts the light. A negative sample does not result in diffraction because no antigen-antibody binding occurs to create the diffraction grating. The presence or absence of a diffraction signal differentiates between positive and negative samples, and the intensity of the signal provides a quantitative measure of the analyte concentration. The technique is demonstrated with a quantitative assay of choriogonadotropin in serum.
Tsay
Y G
YG
Adeza Biomedical Corp., Sunnyvale, CA 94089.
Lin
C I
CI
Lee
J
J
Gustafson
E K
EK
Appelqvist
R
R
Magginetti
P
P
Norton
R
R
Teng
N
N
Charlton
D
D
D015374:Biosensing Techniques; D001826:Body Fluids / Q000737:chemistry; D006063:Chorionic Gonadotropin / Q000032:analysis / Q000276:immunology; D006801:Humans; D007118:Immunoassay; D055095:Optics and Photonics
D006063:Chorionic Gonadotropin