Patent ID: 8580578

Claim:
A method of determining the amount of one or more binding partners in a test sample comprising: (a) illuminating a biosensor with light, wherein the biosensor comprises an optical grating; a substrate layer that supports the optical grating; the optical grating being replicated from a master grating structure by causing a liquid to harden after dispensing the liquid between the master grating structure and the substrate layer, wherein the optical grating comprises the hardened liquid and wherein the optical grating comprises features having a depth and a cross-sectional period; and one or more specific binding substances immobilized on a surface of the optical grating; wherein, when the biosensor is illuminated a resonant grating effect is produced on the reflected radiation spectrum, and wherein the depth and cross-sectional period of the optical grating are less than the wavelength of the resonant grating effect; (b) applying a test sample comprising one or more binding partners to the biosensor; (c) illuminating the biosensor with light; and (d) detecting reflected wavelength of light from the biosensor; and (e) (i) comparing the reflected wavelength of light from the biosensor to positive and negative controls; or (ii) comparing the reflected wavelength of light from the biosensor to a reflected wavelength of light detected from the biosensor prior to the applying the test sample to the biosensor, wherein the amount of one or more binding partners in a test sample is detected.