A novel encoding system and methods for determining the location and/or identity of a particular item or component of interest is provided. In particular, the present invention utilizes a "barcode" comprising one or more sizes of semiconductor nanocrystals (quantum dots) having characteristic spectral emissions, to either "track" the location of a particular item of interest or to identify a particular item of interest. The semiconductor nanocrystals used in the inventive "barcoding" scheme can be tuned to a desired wavelength to produce a characteristic spectral emission in narrow spectral widths, and with a symmetric, nearly Gaussian line shape, by changing the composition and size of the quantum dot. Additionally, the intensity of the emission at a particular characteristic wavelength can also be varied, thus enabling the use of binary or higher order encoding schemes. The information encoded by the quantum dot can be spectroscopically decoded, thus providing the location and/or identity of the particular item or component of interest. In particular, a single primary light source can be used to decode the inventive barcode. In particularly preferred embodiments, the present system and method is used in applications to security systems, to the tracking of consumer items such as jewelry, vehicles, or paper. In other particularly preferred embodiments, the present system and method is used in applications for biochemistry to track the location of biomolecules such as DNA sequences, combinatorial chemistry, and genomics for encoding and probe identifiers.
This application Related Applications claims priority to the co-pending provisional application U.S. Patent Application Ser. No. 60/101,046 entitled "Inventory Control" filed on Sep. 18, 1998, which is incorporated in its entirety by reference. This application is related to the following application which was filed in even day herewith and which is incorporated in its entirety by reference: application entitled "Biological Applications of Quantum Dots". Additionally, this application is also related to the following application, which was filed on Sep. 18, 1998, and which is incorporated in its entirety by reference: application entitled "Water Soluble Luminescent Nanocrystals".
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A material includes various encrypted information such as product type information, product history information and authentication judging information by using an information presenting substance exhibiting line spectrums and associated with certain encrypted information corresponding to the line spectrums. Line spectrum of the information presenting substance is detected by irradiating electromagnetic waves to the material. Since the line spectrum is narrow in half-width and strong in light emitting intensity, the distinctiveness is high and therefore the encrypted information included in the material can be specified assuredly, enabling the simple and assured identification of the material.
A method for preparing water-stable semiconductor nanocrystal complexes that can be stably coupled to tertiary molecules using a self-assembled coating of diblock polymers. The diblock polymers have hydrophilic ends containing hydrophilic functional groups and hydrophobic ends containing hydrophobic functional groups. The diblock polymers are assembled around a semiconductor nanocrystal having a lyophilic surface outer layer. The diblock polymers are further crosslinked via bridging molecules that link adjacent diblock polymers through the hydrophilic functional groups of the hydrophilic ends of the diblock polymers to form a semiconductor nanocrystal complex. The functional groups present on the outer surface of the amphiphilic diblock polymer may serve as attachment sites for coupling tertiary molecules to the semiconductor nanocrystal complex.
The present invention relates to nanocrystals consisting of a homogeneous ternary or quaternary alloy having the composition M1.sub.1-xM2.sub.xA and M1.sub.1-xM2.sub.xA.sub.yB.sub.1-y, respectively, a process for its production, as well as to uses of such nanocrystals such as as short wavelength light-emitting devices, and in the detection of analytes, in particular biomolecules.
The present invention provides new compositions containing colloidal nanocrystals with high photoluminescence quantum yields, new synthetic methods for the preparation of highly luminescent colloidal nanocrystals, as well as methods to control the photoluminescent properties of colloidal nanocrystals. The new synthetic methods disclosed herein allow photoemission brightness (quantum yield) to be correlated with certain adjustable nanocrystal growth parameters associated with a given synthetic scheme.
A method of detecting target biological molecules in a target sample is provided. The method includes using spectral, temporal, and polarization characteristics of emitted light from water-stable semiconductor nanocrystal complexes to detect the presence of target biological molecules in a target sample.
