Microparticle-based methods and systems and applications thereof

Abstract

Microparticle-based analytical methods, systems and applications are provided. Specifically, the use of resonant resonant light scattering as an analytical method for determining either or both a particle's identity and the presence and optionally, the concentration of one or more particular target analytes is described. Applications of these microparticle-based methods in biological and chemical assays are also disclosed.

1 - 47 . (canceled)  
     
     
         48 . An identifiable particle comprising: 
 (a) a substantially spherical core;    (b) a capture probe affixed to the outer surface of the particle;    wherein: 
 1) the particle is characterized by a unique resonant light scattering signature when scanned over an analytical wavelength range of about 1 to about 20 nanometers over a range of optical wavelengths of about 275 nanometers to about 1900 nanometers;  
 2) the particle is about 100 micrometers in diameter or less;  
 3) the particle has a refractive index between about 1.6 and about 2.1 over the analytical wavelength range; and  
 4) the particle is substantially non-fluorescing over the analytical wavelength range.  
   
     
     
         49 . A particle according to  claim 48  optionally having one or more layers overlaying the core.  
     
     
         50 . A particle according to  claim 49  wherein the one or more layers are optically active.  
     
     
         51 . A particle according to  claim 49  wherein the one or more layers are biologically active.  
     
     
         52 . A particle according to  claim 49  wherein the one or more layers are chemically active.  
     
     
         53 . A particle according to either of claims  51  or  52  wherein the layers have a thickness ranging from about 1 nanometer to about 10 micrometers.  
     
     
         54 . A particle according to  claim 49  wherein the one or more layers have a thickness of about 50 nanometers to about 20 micrometers.  
     
     
         55 . An identifiable particle comprising: 
 (a) a substantially spherical core;    (b) a capture probe affixed to the outer surface of the particle;    wherein: 
 1) the particle is characterized by a unique resonant light scattering signature when scanned over an analytical wavelength range of about 1 to about 20 nanometers over a range of optical wavelengths of about 275 nanometers to about 1900 nanometers;  
 2) the particle is about 100 micrometers in diameter or less;  
 3) the particle has a refractive index between about 1.6 and about 2.1 over the analytical wavelength range; and  
 4) the particle is substantially non-fluorescing over the analytical wavelength range;  
   wherein the particle comprises: 
 i) one or more optically active layers having a thickness between about 50 nanometers and about 20 micrometers; and  
 ii) one or more biologically active or chemically active substantially transparent outer layers of thickness between about 1 nanometer to 10 micrometers, said layers overlaying the layer of (i).  
   
     
     
         56 . A particle according to  claim 48  wherein the core is comprised of materials selected from the group consisting of; glasses, semiconducting materials, optically absorbing materials, metals, magnetic materials, and composites thereof.  
     
     
         57 . A particle according to  claim 48  wherein the capture probe is selected from the group consisting of proteins, nucleic acids, peptide nucleic acids, one member of a binding pair, antibodies, biological cells, microorganisms, cell membrane fragments, cellular organelles, receptors, viruses, viral fragments, bacteriophage, bacteriophage fragments, organic ligands, and organometallic ligands.  
     
     
         58 . A particle according to  claim 57  wherein the one member of a binding pair is selected from the binding pair combinations consisting of: antigen/antibody; Protein A/antibody, Protein G/antibody, hapten/anti-hapten, biotin/avidin, biotin/streptavidin, folic acid/folate binding protein; hormone/hormone receptor, lectin/carbohydrate, enzyme/enzyme cofactor, enzyme/substrate, enzyme/inhibitor, peptide nucleic acid/complimentary nucleic acid, polynucleotide/polynucleotide binding protein, vitamin B12/intrinsic factor; complementary nucleic acid segments; pairs comprising sulfhydryl reactive groups, pairs comprising carbodiimide reactive groups, and pairs comprising amine reactive groups.  
     
     
         59 . A population of identifiable particles according to  claim 48 .  
     
     
         60 - 70 . (canceled)