Guided mode resonant filter biosensor using a linear grating surface structure
View Patent ↗Methods and compositions are provided for detecting biomolecular interactions. The use of labels is not required and the methods can be performed in a high-throughput manner. The invention also provides optical devices useful as narrow band filters.
1. A detection system comprising:
(a) a biosensor, wherein the biosensor comprises:
(i) a one-dimensional grating surface structure comprised of a material having a low refractive index;
(2) a high refractive index material layer that is applied on top of the low refractive index one-dimensional grating layer; and
(3) one or more specific binding substances immobilized on a surface of the high refractive index layer opposite of the one-dimensional grating surface structure comprised of a material having a low refractive index; wherein the one or more specific binding substances do not comprise detection labels; wherein, when the biosensor is illuminated a resonant grating effect is produced on a reflected radiation spectrum; and wherein the cross-sectional period of the one-dimensional grating is less than the wavelength of the resonant grating effect;
(b) a light source that directs light to the biosensor; and
(c) a detector that detects light reflected or transmitted from the biosensor.
2. The detection system of claim 1 , wherein a polarizing filter is present between the light source and the biosensor.
3. The detection system of claim 1 , further comprising a fiber probe comprising one or more illuminating optical fibers that are connected at a first end to the light source, and one or more collecting optical fibers connected at a first end to the detector, wherein the second ends of the illuminating and collecting fibers are arranged in line with a collimating lens that focuses light onto the biosensor.
4. The detection system of claim 3 , wherein the illuminating fiber and the collecting fiber are the same fiber.
5. The detection system of claim 1 , wherein the light source illuminates the biosensor from its top surface or from its bottom surface.
6. The detection system of claim 1 , wherein the one or more specific binding substances are arranged in an array of distinct locations on the high refractive index material.