Label-free high-throughput optical technique for detecting biomolecular interactions
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 biosensor composition comprising one or more biosensors on a tip of a multi-fiber optic probe, wherein the biosensors comprise:
(i) a two-dimensional grating;
(ii) a substrate that supports the two-dimensional grating; wherein the refractive index of the two-dimensional grating is greater than the refractive index of the substrate; and
(iii) one or more specific binding substances immobilized on the surface of the two-dimensional grating opposite of the substrate layer; wherein when the biosensor is illuminated a resonant grating effect is produced on a reflected radiation spectrum, and wherein the depth and period of the two-dimensional grating are less than the wavelength of the resonant grating effect.
2. The biosensor of claim 1 , wherein the one or more specific binding substances do not comprise detection labels.
3. The biosensor of claim 1 , wherein the two-dimensional grating is comprised of a repeating pattern of shapes selected from the group consisting of lines, squares, circles, ellipses, triangles, trapezoids, sinusoidal waves, ovals, rectangles and hexagons.
4. The biosensor of claim 1 , wherein the two-dimensional grating is comprised of a material selected from the group consisting of zinc sulfide, titanium dioxide, tantalum oxide, and silicon nitride.
5. The biosensor of claim 1 , wherein the two-dimensional grating has a period of about 0.01 microns to about 1 micron and a depth of about 0.01 microns to about 1 micron.
6. The biosensor of claim 1 , wherein the one or more biosensors are each about 1 mm 2 to about to about 5 mm 2 in size.
7. A method of detecting binding of one or more specific binding substances to their respective binding partners in vitro or in vivo comprising:
(a) inserting the tip of the fiber optic probe of claim 1 into a vessel comprising a test sample or a body of a human or animal;
(b) illuminating the biosensor with light;
(c) detecting reflected wavelength of light from the biosensor;
wherein, if the one or more specific binding substances have bound to their respective binding partners, then the reflected wavelength of light is shifted.