Lyophilization of colloidal metals for surface enhanced Raman scattering

Abstract

An assay and method of making same for use in SERS spectroscopy. The assay includes colloidal particles of a metal, which have been lyophilized. The lyophilized particles of metal produce a SERS active solution when reconstituted. The lyophilized particles of metal may be provided in a container in an assay system.

What is claimed is:  
     
         1 . An assay for use in SERS spectroscopy, the assay comprising lyophilized colloidal particles of a metal, which when reconstituted, produce a SERS active solution.  
     
     
         2 . The assay of  claim 1 , wherein the metal is a noble metal.  
     
     
         3 . The assay of  claim 1 , wherein the assay is used in SERS spectroscopy to determine the concentration of an unknown solution.  
     
     
         4 . The assay of  claim 1 , further comprising a material for preventing the particles from sticking to one another.  
     
     
         5 . The assay of  claim 4 , wherein the material comprises a wax-like material.  
     
     
         6 . The assay of  claim 4 , wherein the material comprises polyethylene glycol.  
     
     
         7 . An assay system for use in SERS spectroscopy, the assay system comprising: 
 a container;    lyophilized colloidal particles of a metal disposed in a first section of the container;    wherein reconstitution of the lyophilized colloidal particles of a metal produce a SERS active solution.    
     
     
         8 . The assay system of  claim 7 , wherein the metal is a noble metal.  
     
     
         9 . The assay system of  claim 7 , further comprising a closure for sealing the container.  
     
     
         10 . The assay system of  claim 7 , further comprising a reagent disposed in a second section of the container, the reagent for coupling an analyte to a SERS active metal.  
     
     
         11 . The assay system of  claim 10 , wherein the second section of the container is remote from the first section of the container.  
     
     
         12 . The assay system of  claim 7 , further comprising a material for preventing the particles from sticking to one another.  
     
     
         13 . The assay system of  claim 12 , wherein the material comprises a wax-like material.  
     
     
         14 . The assay system of  claim 12 , wherein the material comprises polyethylene glycol.  
     
     
         15 . The assay system of  claim 12 , further comprising a pretreatment disposed on an inner surface of the container, the pretreatment for preventing the particles from sticking to one another and sticking to the inner surface of the container.  
     
     
         16 . The assay system of  claim 15 , wherein the pretreatment comprises a wax-like material.  
     
     
         17 . The assay system of  claim 15 , wherein the pretreatment comprises polyethylene glycol.  
     
     
         18 . The assay system of  claim 7 , further comprising a pretreatment disposed on an inner surface of the container, the pretreatment for preventing the particles from sticking to one another and sticking to the inner surface of the container.  
     
     
         19 . The assay system of  claim 18 , wherein the pretreatment comprises a wax-like material.  
     
     
         20 . The assay system of  claim 18 , wherein the pretreatment comprises polyethylene glycol.  
     
     
         21 . The assay system of  claim 7 , wherein the assay is used in SERS spectroscopy to determine the concentration of an unknown solution.  
     
     
         22 . The assay system of  claim 7 , wherein the first section of the container includes a plurality of wells and lyophilized colloidal particles of a metal disposed in each of the wells.  
     
     
         23 . The assay system of  claim 22 , wherein the lyophilized colloidal particles of metal include an antibody.  
     
     
         24 . The assay system of  claim 23 , wherein the assay system forms a Surface Enhanced Raman ImmunoAssay.  
     
     
         25 . A method of producing an assay for use in SERS spectroscopy, the method comprising: 
 providing a suspension of colloidal particles of metal;    lyophilizing the suspension of colloidal particles of metal to produce the assay, which when reconstituted, produce a SERS active solution.    
     
     
         26 . The method of  claim 25 , wherein the metal is a noble metal.  
     
     
         27 . The method of  claim 25 , further comprising the step of mixing the colloidal particles of metal with a material prior to the lyophilizing step, the material preventing the particles from sticking to one another.  
     
     
         28 . The method of  claim 27 , wherein the material comprises a wax-like material.  
     
     
         29 . The method of  claim 27 , wherein the material comprises polyethylene glycol.  
     
     
         30 . A method of making an assay system for use in SERS spectroscopy, the method comprising the steps of: 
 providing a container;    placing a suspension of colloidal particles of a metal in a first section of the container;    lyophilizing the suspension of colloidal particles of the metal to produce an assay, which when reconstituted, produce a SERS active solution.    
     
     
         31 . The method of  claim 30 , wherein the metal is a noble metal.  
     
     
         32 . The method of  claim 30 , further comprising the step of mixing the suspension of colloidal particles of metal with a material prior to the placing step, the material preventing the particles from sticking to one another.  
     
     
         33 . The method of  claim 32 , wherein the material comprises a wax-like material.  
     
     
         34 . The method of  claim 32 , wherein the material comprises polyethylene glycol.  
     
     
         35 . The method of  claim 32 , wherein the container providing step includes applying a pretreatment to an inner surface of the container, the pretreatment for preventing the particles from sticking to one another and sticking to the inner surface of the container.  
     
     
         36 . The method of  claim 35 , wherein the pretreatment comprises a wax-like material.  
     
     
         37 . The method of  claim 35 , wherein the pretreatment comprises polyethylene glycol.  
     
     
         38 . The method of  claim 30 , further comprising the step of placing a reagent in a second section of the container, the reagent for coupling an analyte to a SERS active metal.  
     
     
         39 . The method of  claim 38 , wherein the lyophilizing step further includes lyophilizing the reagent.  
     
     
         40 . The method of  claim 38 , wherein the second section of the container is remote from the first section of the container.  
     
     
         41 . The method of  claim 30 , where the container providing step includes applying a pretreatment to an inner surface of the container, the pretreatment for preventing the particles from sticking to one another and sticking to the inner surface of the container.  
     
     
         42 . The method of  claim 41 , wherein the pretreatment comprises a wax-like material.  
     
     
         43 . The method of  claim 41 , wherein the pretreatment comprises polyethylene glycol.  
     
     
         44 . A method of analyzing a material, the method comprising the steps of: 
 providing a container;    placing a suspension of colloidal particles of a metal in a first section of the container;    lyophilizing the colloidal particles of the metal to produce an assay;    simultaneously reconstituting and mixing the assay with the material to be analyzed to produce a SERS active solution;    performing SERS spectroscopy on the SERS active solution.    
     
     
         45 . The method of  claim 44 , wherein the metal is a noble metal.  
     
     
         46 . The method of  claim 44 , further comprising the step of mixing the suspension of colloidal particles of metal with a material prior to the placing step, the material preventing the particles from sticking to one another.  
     
     
         47 . The method of  claim 46 , wherein the material comprises a wax-like material.  
     
     
         48 . The method of  claim 46 , wherein the material comprises polyethylene glycol.  
     
     
         49 . The method of  claim 46 , wherein the container providing step includes applying a pretreatment to an inner surface of the container, the pretreatment for preventing the particles from sticking to one another and sticking to the inner surface of the container.  
     
     
         50 . The method of  claim 49 , wherein the pretreatment comprises a wax-like material.  
     
     
         51 . The method of  claim 49 , wherein the pretreatment comprises polyethylene glycol.  
     
     
         52 . The method of  claim 44 , further comprising the step of placing a reagent in a second section of the container, the reagent for coupling an analyte to a SERS active metal.  
     
     
         53 . The method of  claim 52 , wherein the lyophilizing step further includes lyophilizing the reagent.  
     
     
         54 . The method of  claim 52 , wherein the second section of the container is remote from the first section of the container.  
     
     
         55 . The method of  claim 44 , where the container providing step includes applying a pretreatment to an inner surface of the container, the pretreatment for preventing the particles from sticking to one another and sticking to the inner surface of the container.  
     
     
         56 . The method of  claim 55 , wherein the pretreatment comprises a wax-like material.  
     
     
         57 . The method of  claim 55 , wherein the pretreatment comprises polyethylene glycol.  
     
     
         58 . The assay of  claim 1 , further comprising an antibody.  
     
     
         59 . The assay system of  claim 7 , further comprising an antibody.  
     
     
         60 . The method of  claim 25 , further comprising the step of mixing the suspension of colloidal particles of metal with an antibody prior to the lyophilizing step.  
     
     
         61 . The method of  claim 30 , wherein the first section of the container includes a plurality of wells and lyophilized colloidal particles of a metal are placed in each of the wells.  
     
     
         62 . The method of claim  61 , wherein the lyophilized colloidal particles of metal include an antibody.  
     
     
         63 . The method of claim  62 , wherein the assay system forms a Surface Enhanced Raman ImmunoAssay.