Fluorescent Carbon Nanoparticles

Abstract

Disclosed are photoluminescent particles. The particles include a core nano-sized particle of carbon and a passivation agent bound to the surface of the nanoparticle. The passivation agent can be, for instance, a polymeric material. The passivation agent can also be derivatized for particular applications. For example, the photoluminescent carbon nanoparticles can be derivatized to recognize and bind to a target material, for instance a biologically active material, a pollutant, or a surface receptor on a tissue or cell surface, such as in a tagging or staining protocol.

1 - 27 . (canceled) 
     
     
         28 . A nanoparticle comprising a carbon core and a passivation agent coupled to the carbon core, wherein the carbon core is less than about 100 nanometers in size, wherein the nanoparticle is photoluminescent. 
     
     
         29 . The nanoparticle of claim  1 , wherein the carbon core defines a surface, and the surface is photoluminescent due to the presence of the passivation agent coupled to the carbon core. 
     
     
         30 . The nanoparticle of claim  1 , wherein the carbon core defines a surface, and comprises excitation energy traps existing at the surface; and wherein the passivation agent stabilizes at least some of the excitation energy traps to encourage or stabilize the radiative recombination of excitons. 
     
     
         31 . The nanoparticle of claim  1 , wherein the passivation agent forms a coating over at least a portion of the surface of the carbon core; the passivation agent is covalently bound to the surface at multiple locations; and the surface comprises bonding sites. 
     
     
         32 . The nanoparticle of claim  1 , further comprising a material embedded on the surface of the carbon core. 
     
     
         33 . The nanoparticle of claim  5 , wherein the material is chosen from metal and magnetic material. 
     
     
         34 . The nanoparticle of claim  1 , wherein the carbon core comprises a thermally carbonized particle of a carbon-rich polymer. 
     
     
         35 . The nanoparticle of claim  1 , wherein the passivation agent is chosen from poly(lactic acid), poly(ethylene glycol), poly(propionylethylenimine-co-ethylenimine), and poly(vinyl alcohol). 
     
     
         36 . The nanoparticle of claim  1 , wherein the passivation agent comprises a reactive functionality specific to a surface receptor of  E. coli , a surface receptor of  L. monocytogenes , a ligand particular to an antibody, a haptens particular to an antibody, a complete antigen, or an epitope of an antigen. 
     
     
         37 . The nanoparticle of claim  1 , wherein the carbon core comprises carbon, nickel, and yttrium. 
     
     
         38 . The nanoparticle of claim  10 , wherein carbon is present in an amount of about 95%, nickel is present in an amount of about 4%, and yttrium is present in an amount of about 1%, based on the weight of the carbon core. 
     
     
         39 . The nanoparticle of claim  1 , wherein the carbon core is less than about 30 nanometers in size. 
     
     
         40 . The nanoparticle of claim  1 , wherein the carbon core comprises crystalline carbon. 
     
     
         41 . The nanoparticle of claim  1 , wherein the passivation agent is a polymer. 
     
     
         42 . The nanoparticle of claim  1 , wherein the passivation agent is a biopolymer. 
     
     
         43 . The nanoparticle of claim  1 , wherein the passivation agent is covalently bonded to the carbon core. 
     
     
         44 . The nanoparticle of claim  1 , wherein the passivation agent is non-covalently bonded to the carbon core. 
     
     
         45 . The nanoparticle of claim  1 , wherein the passivation agent comprises a protein or a peptide. 
     
     
         46 . The nanoparticle of claim  1 , wherein the passivation agent is bound to a drug. 
     
     
         47 . A luminescent ink comprising a nanoparticle comprising a carbon core and a passivation agent coupled to the carbon core, wherein the carbon core is less than about 100 nanometers in size, wherein the nanoparticle is photoluminescent.