Method of detecting an analyte in a sample using semiconductor nanocrystals as a detectable label

Abstract

The use of semiconductor nanocrystals as detectable labels in various chemical and biological applications is disclosed. The methods find use for detecting a single analyte, as well as multiple analytes by using more than one semiconductor nanocrystal as a detectable label, each of which emits at a distinct wavelength.

1 . A method of detecting one or more target analytes in a sample, comprising:
 (a) providing a sample containing or suspected of containing the one or more target analytes on a solid support;   (b) combining said sample with a semiconductor nanocrystal conjugate, wherein said combining is performed under conditions that allow formation of a complex comprising said conjugate and said analyte, when present;   (c) removing any unbound conjugate; and   (d) detecting the presence of the complex, if present, by monitoring a spectral emission mediated by the semiconductor nanocrystal in the complex, wherein the emission indicates the presence of one or more target analytes in the sample.   
     
     
         2 . The method of  claim 1 , wherein the sample comprises a plurality of target analytes, and the method further comprises:
 (a) providing a conjugate specific for each target analyte, wherein each semiconductor nanocrystal conjugate has an emission spectrum distinct from the other semiconductor nanocrystal conjugates; and   (b) detecting the presence of the target analytes by monitoring the spectral emissions of the sample, wherein the emissions indicate the presence of the target analytes in the sample.   
     
     
         3 . The method of  claim 1 , wherein the one or more analytes is a nucleic acid molecule. 
     
     
         4 .- 10 . (canceled) 
     
     
         11 . The method of  claim 3 , wherein the nucleic acid molecule is a polynucleotide. 
     
     
         12 .- 16 . (canceled) 
     
     
         17 . A method of detecting one or more target analytes in a sample, comprising:
 (a) providing an unlabeled specific-binding molecule on a solid support;   (b) combining a sample containing one or more target analytes or suspected of containing the one or more analytes with said specific-binding molecule, wherein said combining is performed under conditions that allow formation of a first complex comprising said specific-binding molecule and said analyte, when present;   (c) removing any unbound sample;   (d) combining said first complex with a semiconductor nanocrystal conjugate, wherein said combining is performed under conditions that allow formation of a second complex comprising said conjugate and said analyte, when present;   (e) removing any unbound conjugate; and   (f) detecting the presence of the second complex, if present, by monitoring a spectral emission mediated by the semiconductor nanocrystal in the second complex, wherein the emission indicates the presence of one or more target analytes in the sample.   
     
     
         18 . The method of  claim 17 , wherein the method comprises combining a sample comprising a plurality of target analytes with the specific-binding molecule, wherein the method further comprises:
 (a) providing an unlabeled specific-binding molecule on a solid support specific for each target analyte and providing a semiconductor nanocrystal conjugate specific for each target analyte, wherein each semiconductor nanocrystal conjugate has an emission spectrum distinct from the other semiconductor nanocrystal conjugates; and   (b) detecting the presence of the target analytes by monitoring the spectral emissions of the sample, wherein the emissions indicate the presence of the target analytes in the sample.   
     
     
         19 . The method of  claim 17 , wherein the one or more analytes is a nucleic acid molecule. 
     
     
         20 . The method of  claim 19 , wherein the nucleic acid molecule is a polynucleotide. 
     
     
         21 .- 24 . (canceled) 
     
     
         25 . A method of detecting one or more target analytes in a sample, comprising:
 (a) providing a sample containing one or more target analytes or suspected of containing the one or more analytes on a solid support;   (b) combining with said sample a specific-binding molecule, wherein (i) said specific-binding molecule comprises a first member of a binding pair, and (ii) said combining is performed under conditions that allow formation of a first complex comprising said specific-binding molecule and said analyte, when present;   (c) removing any unbound specific-binding molecule;   (d) combining said first complex with a second member of the binding pair, wherein (i) said second member of the binding pair is linked to a first semiconductor nanocrystal; and (ii) said combining is performed under conditions that allow formation of a second complex comprising the binding pair and said one or more analytes; and   (e) detecting the presence of the second complex, if present, by monitoring a spectral emission mediated by the semiconductor nanocrystal in the second complex, wherein the emission indicates the presence of one or more target analytes in the sample.   
     
     
         26 . The method of  claim 25 , wherein the one or more analytes is a nucleic acid molecule. 
     
     
         27 .- 29 . (canceled) 
     
     
         30 . The method of  claim 25 , wherein the one or more analytes is a polynucleotide. 
     
     
         31 . The method of  claim 25 , wherein the specific-binding molecule is a polymerase chain reaction amplification product. 
     
     
         32 .- 34 . (canceled) 
     
     
         35 . The method of  claim 25 , wherein the first member of the binding pair is biotin and the second member of the binding pair is streptavidin or the first member of the binding pair is biotin and the second member of the binding pair is streptavidin. 
     
     
         36 . (canceled) 
     
     
         37 . The method of  claim 25 , wherein the first member of the binding pair is digoxygenin and the second member of the binding pair is an antibody directed against digoxygenin or the first member of the binding pair is fluorescein and the second member of the binding pair is an antibody directed against fluorescein. 
     
     
         38 .- 45 . (canceled) 
     
     
         46 . The method of  claim 1 , wherein the solid support is selected from a membrane, bead, microsphere, and microtiter well or plate. 
     
     
         47 . The method of  claim 17 , wherein the solid support is selected from a membrane, bead, microsphere, and microtiter well or plate. 
     
     
         48 . The method of  claim 17 , wherein the specific-binding molecule is a polymerase chain reaction amplification product. 
     
     
         49 . The method of  claim 25 , wherein the solid support is selected from a membrane, bead, microsphere, and microtiter well or plate. 
     
     
         50 . The method of  claim 31 , wherein the first member of the binding pair is incorporated in the amplification product.