Small organometallic probes

Abstract

Small organometallic probes comprise a core of metal atoms bonded to organic moieties. The metal atoms are gold, silver, platinum, palladium, or combinations thereof. In one embodiment, a multifunctional organometallic probe comprises a core of metal atoms surrounded by a shell of organic moieties covalently attached to the metal atoms, a fluorescent molecule, e.g., fluorescein, covalently attached to one of the organic moieties, and a targeting molecule, e.g., an antibody, covalently attached to another of the organic moieties.

1 . A cluster complex or colloid comprising: 
 a plurality of core particles, each of the core particles being composed of a solid metal; and    a plurality of probe molecules covalently attached to the core particles, the probe molecules functionalizing the cluster complex or colloid to target at least one other substance or to endow the particles with specified properties.    
     
     
         2 . The cluster complex or colloid of  claim 1  wherein the core particles are less than 2 microns in size.  
     
     
         3 . The cluster complex or colloid of  claim 1  wherein the metal of the core particles is gold, platinum, silver, palladium, or combinations thereof.  
     
     
         4 . The cluster complex or colloid of  claim 1  wherein the probe molecules are covalently bonded to the core particles by a specific reaction of the probe molecules with a functional group incorporated into an outer surface of the core particle by means of chemical synthesis or modification, the functional group being selected from the group comprising maleimide, N-hydroxysuccinimide, Sulfo-N-hydroxysuccinimide, aliphatic amine, 1,2-dihydroxy, aldehyde, nitrilotriaceitic acid (NTA) or its chelate with nickel, copper, iron, cobalt, or other transition metal.  
     
     
         5 . The cluster complex or colloid of  claim 4  further comprising nucleic acids, DNA, or RNA covalently bonded to the core particles by the functional group.  
     
     
         6 . The cluster complex or colloid of  claim 1  wherein the covalently attached probe molecules are selected from the group comprising antibodies, antibody fragments, avidin or streptavidin, peptides, drugs, antigens, hormones, DNA, and RNA.  
     
     
         7 . The clusters or colloids of  claim 1  further comprising a plurality of fluorescently labeled molecules covalently attached to the core particles, wherein the chemistry for covalently attaching the probe molecules and the fluorescently labeled molecules to the core particles controls the fluorophore of the fluorescently labeled molecules.  
     
     
         8 . The cluster complex or colloid of  claim 1  further comprising a plurality of lipid molecules attached to the core particles.  
     
     
         9 . The cluster complex or colloid of  claim 1  further comprising nucleic acids, DNA, or RNA.  
     
     
         10 . The cluster complex or colloid of  claim 1  further comprising a plurality of antibody fragments.  
     
     
         11 . The cluster complex or colloid of  claim 1  further comprising a polymer coating the core particles, the polymer being chosen from a group containing linear or branched polymer with functional groups, polyamino acids, polyethylene derivatives, and mixtures thereof.  
     
     
         12 . The cluster complex or colloid of  claim 1  wherein the core particles are composed of gold and the probe molecules are fluorescent dyes.  
     
     
         13 . The cluster complex or colloid of  claim 12  wherein the fluorescent dye is Hoescht-33258.  
     
     
         14 . The cluster complex or colloid of  claim 1  wherein the probe molecule is streptavidin.  
     
     
         15 . A method for detecting a substance comprising mixing a sample suspected of containing the substance with a cluster complex or a colloid comprising a plurality of metal core particles and a plurality of probe molecules covalently attached to the core particles, the probe molecules functionalizing the cluster complex or colloid to target the substance.  
     
     
         16 . The method of 15 further comprising the step of detecting the substance with a piezoelectric crystal mass measuring device.  
     
     
         17 . The method of  claim 15  further comprising the step of detecting the substance by using changes in reflected light from a surface.  
     
     
         18 . The method of  claim 15  further comprising the step of detecting the substance using light microscopy.  
     
     
         19 . The method of  claim 15  further comprising the step of visualizing the localization or distribution of the substance within cells, tissue sections, organelles or organs using light microscopy.  
     
     
         20 . The method of  claim 15  further comprising the step of detecting the substance using fluorescent microscopy.  
     
     
         21 . The method of  claim 15  further comprising the step of visualizing the localization or distribution of the substance within cells, tissue sections, organelles or organs using fluorescent microscopy.  
     
     
         22 . The method of  claim 15  further comprising the step of detecting the substance using confocal microscopy.  
     
     
         23 . The method of  claim 15  further comprising the step of visualizing the localization or distribution of the substance within cells, tissue sections, organelles or organs using confocal microscopy.  
     
     
         24 . The method of  claim 15  further comprising the step of detecting the substance using electron microscopy.  
     
     
         25 . The method of  claim 15  further comprising the step of visualizing the localization or distribution of the substance within cells, tissue sections, organelles or organs using electron microscopy.  
     
     
         26 . The method of  claim 15  wherein the cluster complex or colloid further comprises a plurality of fluorescently labeled molecules covalently attached to the core particles, the chemistry for covalently attaching the probe molecules and the fluorescently labeled molecules to the core particles controls the fluorophore of the fluorescently labeled molecules, and wherein the method further comprises the step of detecting the substance using both light, fluorescence or confocal microscopy and electron microscopy.  
     
     
         27 . The method of  claim 15  wherein the cluster complex or colloid further comprises a plurality of fluorescently labeled molecules covalently attached to the core particles, the chemistry for covalently attaching the probe molecules and the fluorescently labeled molecules to the core particles controls the fluorophore of the fluorescently labeled molecules, and wherein the method further comprises the step of visualizing the localization or distribution of the substance within cells, tissue sections, organelles or organs using both light, fluorescence or confocal microscopy and electron microscopy.  
     
     
         28 . The method of  claim 15  further comprising the step of detecting the substance on blots, immunochromatographic lateral flow assay devices, or test strips.  
     
     
         29 . A metal cluster comprising: 
 a plurality of metal core particles; and    a plurality of organic thiols covalently bound to the core particles through a thiol moiety, the organic thiols being selected from the group comprising alkyl thiols, aryl thiols, proteins containing thiol, peptides or nucleic acids with thiol, glutathione, cysteine, thioglucose, thiol benzoic acid, antibodies, lipids, and carbohydrates.    
     
     
         30 . A metal colloid comprising: 
 a plurality of metal colloid particles; and    a plurality of organic thiols covalently bound to the core particles through a thiol moiety, the organic thiols being selected from the group comprising alkyl thiols, aryl thiols, proteins containing thiol, peptides or nucleic acids with thiol, glutathione, cysteine, thioglucose, thiol benzoic acid, antibodies, lipids, and carbohydrates.    
     
     
         31 . A metal colloid comprising: 
 a plurality of metal colloid particles; and    a polymer coating the metal colloid particles.    
     
     
         32 . The metal colloid of  claim 31  further comprising a plurality of covalently bonded molecules selected from the group including proteins, peptides, antibodies, lipids, carbohydrates, nucleic acids, drugs, and hormones.  
     
     
         33 . A process for coating metal colloid particles comprising synthesizing the metal colloid in the presence of a polymer.  
     
     
         34 . The process of  claim 33  further comprising the step of stabilizing the polymer coating on the metal colloid particle by warming the coated particle to 60°-100° C., microwave heating, chemical crosslinking, continued polymerization, or photocrosslinking.  
     
     
         35 . A process for coating metal colloid particles comprising mixing preformed metal colloid particles with a polymer.  
     
     
         36 . The process of  claim 35  further comprising the step of stabilizing the polymer coating on the metal colloid particle by warming the coated particle to 60°-100° C., microwave heating, chemical crosslinking, continued polymerization, or photocrosslinking.  
     
     
         37 . A process for covalently incorporating organometallic particles into nucleic acids comprising using an organometallic particle containing a nucleic acid base or nucleic acid analog as a substrate in automated nucleic acid synthesis.  
     
     
         38 . A process for covalently incorporating organometallic particles into nucleic acids comprising using an organometallic particle attached to a nucleic acid base or analog in enzymatic nucleic acid synthesis.  
     
     
         39 . A process for covalently incorporating organometallic particles into nucleic acids comprising reacting an organometallic particle with functional groups incorporated into nucleic acids.  
     
     
         40 . A process for covalently incorporating organometallic particles into nucleic acids comprising reacting organometallic particles containing photoactive groups with nucleic acids.  
     
     
         41 . A process of exchanging thiol-containing molecules on metal particles by incubating preformed metal particles containing bound thiol molecules with a new thiol-containing molecule, whereby the new thiol-containing molecule attaches to the metal particle.  
     
     
         42 . The process of  claim 41  where the new thiol-containing molecule is chosen from whole IgG and Fab′ antibody fragments.  
     
     
         43 . A method for imparting specific chemical, spectroscopic, or electrochemical properties or functions to a larger macromolecular array or construct by covalently bonding a plurality of probe molecules onto a plurality of metal core particles, the probe molecules being covalently bonded to the core particles by a specific reaction of the probe molecules with a functional group incorporated into an outer surface of the core particle by means of chemical synthesis or modification, the functional group being selected from the group comprising maleimide, N-hydroxysuccinimide, Sulfo-N-hydroxysuccinimide, aliphatic amine, 1,2-dihydroxy, aldehyde, nitrilotriaceitic acid (NTA) or its chelate with nickel, copper, iron, cobalt, or other transition metal.  
     
     
         44 . A method for detecting changes in the conformation or binding of probe molecules attached to specific targets, the probe molecules being covalently attached to metal core particles, the probe molecules functionalizing the cluster complex or colloid to the target, the method comprising measuring changes in the fluorescence properties of conjugated molecules labeled with fluorescent tags.