Method for tagging material with surface-enhanced spectroscopy (ses)-active composite nanoparticles

Abstract

Metal nanoparticles associated with a spectroscopy-active (e.g., Raman-active) analyte and surrounded by an encapsulant are useful as sensitive optical tags detectable by surface-enhanced spectroscopy (e.g., surface-enhanced Raman spectroscopy).

1 . A method of tagging a material, comprising the steps of:
 providing at least one particle comprising:   a surface-enhanced spectroscopy (SES)-active metal nanoparticle core, one or more Raman-active molecules associated with or attached to said (SES)-active metal nanoparticle core, and an encapsulant surrounding said SES-active metal nanoparticle core and said Raman-active molecules, wherein said encapsulant comprises glass or a polymer, and   associating a material with said at least one particle thereby forming a tagged material.   
     
     
         2 . The method of  claim 1 , wherein said metal nanoparticle core comprises Au, Ag, Cu, Na, Al, or Cr. 
     
     
         3 . The method of  claim 2 , wherein said metal nanoparticle core comprises Au. 
     
     
         4 . The method of  claim 2 , wherein said metal nanoparticle core comprises Ag. 
     
     
         5 . The method of  claim 1 , wherein said metal nanoparticle core has a diameter less than about 200 nm. 
     
     
         6 . The method of  claim 5 , wherein said metal nanoparticle core has a diameter between about 20 nm and about 200 nm. 
     
     
         7 . The method of  claim 6 , wherein said metal nanoparticle core has a diameter between about 40 nm and about 100 nm. 
     
     
         8 . The method of  claim 1 , wherein said encapsulant has a thickness less than about 1 micron. 
     
     
         9 . The method of  claim 8 , wherein said encapsulant has a thickness between about 1 nm and about 40 nm. 
     
     
         10 . The method of  claim 9 , wherein said encapsulant has a thickness between about 5 nm and about 15 nm. 
     
     
         11 . The method of  claim 1 , wherein said metal nanoparticle core comprises an alloy of metals comprising at least one metal chosen from Au, Ag, Cu, Na, Al, and Cr. 
     
     
         12 . The method of  claim 1 , wherein more than one of said Raman-active molecules forms a submonolayer coating on said metal nanoparticle. 
     
     
         13 . The method of  claim 1 , wherein more than one of said Raman active molecules forms a monolayer coating on said metal nanoparticle. 
     
     
         14 . The method of  claim 1 , wherein more than one of said Raman-active molecules forms a multilayer coating on said metal nanoparticle. 
     
     
         15 . The method of  claim 1 , wherein said encapsulant comprises glass oxide (SiO x ). 
     
     
         16 . The method of  claim 1 , further comprising acquiring a surface-enhanced spectrum (SES) spectrum from said material, wherein said SES spectrum is obtained by a method chosen from SERS, SERRS, SEHRRS, and SEIRA. 
     
     
         17 . The method of  claim 1 , wherein said Raman active molecule comprises a Raman-active aromatic molecule. 
     
     
         18 . The method of  claim 1 , wherein said material is a solid. 
     
     
         19 . The method of  claim 1 , wherein said material comprises a liquid. 
     
     
         20 . The method of  claim 19 , wherein said material is ink, a paint, or an oil. 
     
     
         21 . The method of  claim 1 , wherein said material comprises a material chosen from paper, a textile, a polymer, or a pharmaceutical. 
     
     
         22 . The method of  claim 21 , wherein said material comprises paper. 
     
     
         23 . The method of  claim 21 , wherein said material comprises a textile. 
     
     
         24 . The method of  claim 21 , wherein said material comprises a polymer. 
     
     
         25 . The method of  claim 21 , wherein said material comprises a pharmaceutical. 
     
     
         26 . The method of  claim 1  further comprising acquiring a SES surface-enhanced spectrum from said tagged material. 
     
     
         27 . A method of tagging a material, comprising the steps of:
 providing a material,   associating with said material a plurality of particles, each said particle comprising: a surface-enhanced spectroscopy (SES)-active metal nanoparticle core, one or more Raman-active molecules associated with or attached to said (SES)-active metal nanoparticle core, and an encapsulant surrounding said SES-active metal nanoparticle core and said one or more Raman-active molecules, wherein said encapsulant comprises glass or a polymer, wherein each of said particles has a distinct Raman spectrum, thereby forming a tagged material.   
     
     
         28 . The method of  claim 27 , further comprising the step of identifying said tagged material based on spectral information encoded by said particles. 
     
     
         29 . The method of  claim 28 , wherein the identification step provides information relating to the manufacturing process or supply chain of said tagged material. 
     
     
         30 . The method of  claim 28 , further comprising the step of authenticating said material based on a reference spectrum. 
     
     
         31 . The method of  claim 27  further comprising acquiring a surface-enhanced spectrum from said tagged material. 
     
     
         32 . The method of  claim 1 , wherein the step of associating a material with said at least one particle further comprises the incorporation of said at least one particle into said material during the production of said material. 
     
     
         33 . The method of  claim 1 , wherein said material is a finished product. 
     
     
         34 . The method of  claim 1 , wherein said at least one particle is associated with said material by chemical or physical means.