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 - 2 . (canceled)  
     
     
         3 . A method for the identification of an analyte comprising: 
 (a) providing light scanning source which produces light over an analytical wavelength range;    (b) providing at least two substantially spherical identifiable particles;    (c) applying at least one capture probe to the particles of (b) which binds to the surface of the particle, the at least one capture probe having affinity for at least one analyte;    (d) scanning each particle of (c) one or more times over the analytical wavelength range to produce at least one first reference resonant light scattering signature for each particle of (c), said first resonant light scattering signature uniquely identifying each particle;    (e) correlating the at least one capture probe with each identified particle of (d);    (f) contacting the particle of (e) with a sample suspected of containing at least one analyte where, if the analyte is present, binding occurs between the at least one capture probe and the at least one analyte, the analyte comprising a detectable label; and    (g) identifying one or more analytes on the basis of the correlation of step (e) and the detectable label of the analyte.    
     
     
         4 - 5 . (canceled)  
     
     
         6 . A method according to of  claim 3  wherein the particle is scanned over the analytical wavelength range prior to applying the capture probe to produce an identifying resonant light scattering signature.  
     
     
         7 - 12 . (canceled)  
     
     
         13 . A method according to  claim 3  wherein the detectable label is selected from the group consisting of fluorescent moieties, chemiluminescent moieties, particles, enzymes, radioactive tags, light emitting moieties, light absorbing moieties, intercalating dyes and members of binding pairs.  
     
     
         14 - 15 . (canceled)  
     
     
         16 . A method according to  claim 3  wherein the particle is about 100 micrometers in diameter or less.  
     
     
         17 . A method according to  claim 3  wherein the particle is about 75 micrometers in diameter or less.  
     
     
         18 . A method according to  claim 3  wherein the particle is about 50 micrometers in diameter or less.  
     
     
         19 . A method according to  claim 3  wherein the particle is substantially transparent to light over the analytical wavelength range.  
     
     
         20 . A method according to  claim 3  wherein the particle comprises: 
 a) a substantially spherical core; and    b) one or more layers overlaying the core;    wherein the one or more layers is substantially transparent to light over the analytical wavelength range.    
     
     
         21 . A method according to  claim 20  wherein the one or more layers are optically active.  
     
     
         22 . A method according to  claim 20  wherein the one or more layers are biologically active.  
     
     
         23 . A method according to  claim 20  wherein the one or more layers are chemically active.  
     
     
         24 . A method according to either of claims  22  or  23  wherein the layers have a thickness ranging from about 1 nanometer to about 10 micrometers.  
     
     
         25 . A method according to  claim 21  wherein the core is light absorbing.  
     
     
         26 . A method according to  claim 20  wherein the one or more layers has a thickness of about 1 nanometer to about 20 micrometers.  
     
     
         27 . A method according to  claim 21  wherein the one or more layers have a thickness of about 50 nanometers to about 20 micrometers.  
     
     
         28 . A method according to  claim 20  wherein the core is comprised of materials selected from the group consisting of: glasses, silica, polystyrene, polyester, polycarbonate, acrylic polymers, polyacrylamide, polyacrylonitrile, polyamide, fluoropolymers, silicone, celluloses, semiconducting materials, optically absorbing materials, metals, magnetic materials, minerals, nanoparticles, colloidal particles, metal oxides, metal sulfides, metal selenides, and composites thereof.  
     
     
         29 . A method according to  claim 28  wherein the magnetic material is iron oxide.  
     
     
         30 . A method according to  claim 20  wherein the core is hollow.  
     
     
         31 . A method according to  claim 20  wherein the layers are comprised of materials independently selected from the group consisting of: glasses, silica, polystyrene, polyester, polycarbonate, acrylic polymers, polyacrylamide, polyacrylonitrile, polyamide, fluoropolymers, silicone, celluloses, polyelectrolytes, minerals, nanoparticles, colloidal particles, metal oxides, metal sulfides, metal selenides, and composites thereof.  
     
     
         32 . A method according to any of claims  1 - 5  wherein the particle is comprised of glass having an index of refraction of about 1.45 to about 2.1 over the analytical wavelength range.  
     
     
         33 . A method according to  claim 3  wherein the at least one 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.  
     
     
         34 . A method according to  claim 33  wherein the at least one analyte is present in a sample comprising sample matrix components.  
     
     
         35 . A method according to  claim 3  wherein the at least one analyte is selected from the group consisting of proteins, nucleic acids, peptide nucleic acids, biological cells, microorganisms, cell membrane fragments, cellular organelles, antibodies, receptors, viruses, viral fragments, bacteriophage, bacteriophage fragments, and one member of a binding pair.  
     
     
         36 . (canceled)  
     
     
         37 . A method according to  claim 33  wherein the one member of a binding pair is selected from the binding pair combinations consisting of: antigen/antibody, antigen/antibody fragment, 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.  
     
     
         38 . A method according to  claim 35  wherein the one member of a binding pair is selected from the binding pair combinations consisting of: antigen/antibody, antigen/antibody fragment, 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.  
     
     
         39 . A method according to  claim 3  wherein the capture probe is synthesized on the surface of the particle.  
     
     
         40 . A method according to  claim 3  wherein the capture probe is isolated from natural sources or synthesized separately prior to being added to the surface of the particle.  
     
     
         41 . A method according to  claim 34  wherein after applying the capture probe to the particle, the particle is treated to prevent non-specific binding of sample matrix components.  
     
     
         42 . A method according to  claim 34  wherein the particles are coated with a thin film to prevent non-specific binding of components of the sample matrix and then the thin film coating is activated to attach the capture probe.  
     
     
         43 . A method according to  claim 3  wherein the either the first reference or second binding resonant light scattering signature comprises spectral features selected from the group consisting of, peak wavelength positions, peak widths, wavelength intervals among peaks, peak amplitudes, and polarization-dependent properties.  
     
     
         44 . (canceled)  
     
     
         45 . A method according to  claim 3  wherein the particle comprises one of more optically active layers.  
     
     
         46 . A method according to  claim 3  wherein the particle comprises one of more biologically active layers.  
     
     
         47 . A method according to  claim 3  wherein the particle comprises one of more chemically active layers.  
     
     
         48 - 70 . (canceled)