Inventory control

A composition comprising:

• a support;
• an item of interest, wherein said item of interest is attached to said support;
• and
• one or more particle size distributions of quantum dots having characteristic spectral emissions, wherein each of said quantum dots is associated with, attached to, or embedded within said support.

A method for identifying the location or identity of an item of interest comprising:

• providing a composition comprising an item of interest, wherein said item of interest has attached thereto, associated therewith, or embedded within, one or more identifiers that individually or as a group encode information as to the item of interest, wherein said one or more identifiers comprises one or more particle size distributions of quantum dots having characteristic spectral emissions;
• subjecting said composition to a primary light source to obtain a spectral emission for said composition;
• and
• correlating said spectral emission with said item of interest.

A method for identifying the location or identity of an item of interest from other items comprising:

• providing a composition comprising:
• a support;
• an item of interest, wherein said item of interest is attached to said support;
• and
• one or more particle size distributions having characteristic spectral emissions, wherein each of said quantum dots is associated with, attached to, or embedded within said support;
• subjecting said composition to a primary light source to obtain a spectral emission for said composition;
• and
• correlating said spectral emission with said item of interest.

A method for providing an identification unit comprising:

• selecting a desired support, wherein said support contains one or more reactive functional moieties on the surface of, or embedded within said support;
• providing an identifier, wherein said identifier comprises one or more particle size distributions of quantum dots having characteristic spectral emissions, and one or more reactive moieties attached to the outer surface of said one or more quantum dots, wherein said one or more reactive moieties are selected for their ability to react with one or more selected functional moieties on the surface of, or embedded within said solid support;
• and
• associating said quantum dot with said support such that the quantum dot becomes attached to or embedded within the surface of said support by reaction of said reactive moieties on the surface of the quantum dot with reactive moieties on the surface of, or embedded within said support.

A method for identifying a compound having a characteristic of interest comprising:

• providing a library of compounds, wherein each member of said library of compounds is attached to a support, and wherein each support also has attached thereto or embedded therein one or more unique identifiers that individually or as a group encode information as to a particular compound having a particular characteristic of interest, wherein said one or more identifiers comprises one or more sizes of quantum dots having characteristic spectral emissions;
• testing said library of compounds in an assay to identify compounds having a characteristic of interest;
• subjecting each support to a primary light source;
• observing the photoluminescence spectrum for each identifier attached to each support containing a compound of interest;
• and
• identifying said compound of interest by correlating the photoluminescence spectrum with said compound of interest.

A method for identifying a compound comprising:

• providing a library of compounds, wherein each member of said library of compounds is attached to a support and wherein each support also has attached thereto or embedded therein one or more unique identifiers that individually or as a group encode information as to a particular compound, wherein said one or more identifiers comprises one or more sizes of quantum dots having characteristic spectral emissions, and wherein each reaction step of each library of compounds has been recorded at that particular reaction stage by observing the photoluminescence spectrum for each identifier attached to or embedded within each support at that reaction stage;
• testing said library of compounds in an assay to identify compounds having a characteristic of interest;
• and
• identifying said compound of interest by correlating the photoluminescence spectrum with said compound of interest.

A method for recording reaction stages for a compound of interest comprising:

• providing a support;
• providing one or more identifiers, wherein said one or more identifiers is attached to or embedded within said support, and wherein said one or more identifiers comprises one or more sizes of quantum dots having characteristic spectral emissions;
• observing the photoluminescence spectrum for said one or more identifiers to record a particular reaction stage;
• reacting said support with a chemical moiety, wherein said chemical moiety is capable of reaction with other chemical moieties, and wherein said one or more identifiers records the reaction of said particular chemical moiety at that stage;
• and
• repeating the abovementioned steps until a desired compound of interest is obtained and is recorded by observing the photoluminescence spectra for each of the identifiers employed in each of the reaction stages.

A method for identifying a molecule having a characteristic of interest comprising:

• providing a first library of molecules, wherein each member of said library of molecules is attached to a support, and wherein each support also has attached thereto or embedded therein one or more unique identifiers that individually or as a group encode information as to a particular molecule having a particular characteristic of interest, wherein said one or more identifiers comprises one or more particle size distributions of quantum dots having characteristic spectral emissions;
• contacting said first library of molecules with a second library of molecules, wherein each of said molecules has attached thereto or embedded therein one or more unique probes, wherein said one or more probes comprises one or more particle size distributions of quantum dots having characteristic spectral emissions, and wherein the characteristic spectral emissions observed for said second library of molecules is different from the characteristic spectral emissions observed for said first library of molecules;
• observing the photoluminescence spectrum for each support, wherein said photoluminescence spectrum provides information about which of the molecules from the second library of molecules are associated with said first library of molecules, and provides information about the identity of the molecule from said first library of molecules.

A composition comprising a support and more than one composition of semiconductor nanocrystal,

• wherein the semiconductor nanocrystal is bound to the support,
• each composition of semiconductor nanocrystal has a spectral emission distinguishable from the other compositions of semiconductor nanocrystal bound to the support,
• the semiconductor nanocrystal having a size in the range of 12 to 150 Angstroms,
• the semiconductor nanocrystal comprises a semiconductor material and an overcoating on a surface of the semiconductor material, and
• each distinguishable spectral emission is a wavelength, an intensity, a linewidth, or a combination thereof.

A composition comprising a support and more than one particle size distribution and composition of semiconductor nanocrystal,

• wherein the semiconductor nanocrystal is bound to the support,
• each particle size distribution and composition of semiconductor nanocrystal has a spectral emission distinguishable from the other particle size distributions of semiconductor nanocrystal bound to the support,
• the semiconductor nanocrystal comprises a semiconductor an overcoating on a surface of the semiconductor, and
• each distinguishable spectral emission is a wavelength, an intensity, a linewidth, or a combination thereof.