Rotors for immunoassays
The present invention provides an analyte detection system for detecting target analytes in a sample. In particular, the invention provides a detection system in a rotor or disc format that utilizes a centrifugal force to move the sample through the detection system. Methods of using the rotor detection system to detect analytes in samples, particularly biological samples, and kits comprising the rotor detection system are also disclosed.
1. A method for detecting an analyte in a sample comprising
(i) adding the sample to a sample port of a device, the device comprising the sample port and a surface, wherein the surface comprises a single channel in fluid communication with the sample port and a circular flow path at the peripheral edge of the surface, wherein the sample port and/or the channel comprises a conjugate comprising a binding partner that can specifically bind to the analyte, and wherein the circular flow path comprises an immobilized capture ligand capable of binding an analyte-conjugate complex;
(ii) spinning the surface and the sample port about a fixed axis to generate a centrifugal force, wherein the centrifugal force causes the sample added to the sample port to flow through the channel and come into fluid contact with the capture ligand; and
(iii) detecting the binding of the analyte in the sample to the capture ligand.
2. The method of claim 1 , wherein the sample port and/or channel comprises a plurality of conjugates.
3. The method of claim 1 , wherein the circular flow path comprises a plurality of capture ligands.
4. The method of claim 1 , wherein the binding partner is conjugated to a detectable entity.
5. The method of claim 4 , wherein the detectable entity is a metallic nanoparticle or metallic nanoshell.
6. The method of claim 4 , wherein the detectable entity is selected from the group consisting of gold nanoparticles, silver nanoparticles, copper nanoparticles, platinum nanoparticles, cadmium nanoparticles, composite nanoparticles, gold hollow spheres, gold-coated silica nanoshells, and silica-coated gold shells.
7. The method of claim 4 , wherein the detectable entity is an enzyme.
8. The method of claim 7 , wherein the enzyme is selected from the group consisting of alkaline phosphatase, horseradish peroxidase, beta-galactosidase, beta-lactamase, luciferase, myeloperoxidase, and amylase.
9. The method of claim 1 , wherein the surface further comprises at least one absorbing entity located downstream from the capture ligand.
10. The method of claim 2 , wherein the plurality of conjugates comprises at least a first conjugate capable of binding a first analyte and a second conjugate capable of binding a second analyte, wherein the first and second analytes are different.
11. The method of claim 2 , wherein each conjugate in the plurality of conjugates is capable of binding a different analyte.
12. The method of claim 2 , wherein the plurality of conjugates comprise binding partners conjugated to different detectable entities.
13. The method of claim 3 , wherein each of said plurality of immobilized capture ligands specifically binds to a different analyte-conjugate complex.
14. The method of claim 3 , wherein each of said plurality of immobilized capture ligands are capable of specifically binding to the same analyte-conjugate complex.
15. The method of claim 14 , wherein the immobilized capture ligands are immobilized at different concentrations.
16. The method of claim 3 , wherein the plurality of capture ligands are arranged sequentially along the circular path.
17. The method of claim 1 , wherein the sample port comprises a blood separator material that allows plasma from a blood sample to pass into the channel, while retaining cellular material from the blood sample in the sample port.