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US 7,917,298 B1Granted
Nanocrystal taggants
AssigneeNanosys, Inc.
InventorsErik C. Scher, Stephen A. Empedocles
Life of this patent
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Abstract
The compositions, methods and systems of the invention provide nanocrystal taggants for unobtrusive monitoring of objects. Objects can be tagged with nanocrystal taggant compositions for detection of informative invisible emissions on illumination with appropriate excitation wavelengths.
Claims26
A composition for tagging objects, comprising:
- a population of nanocrystals comprising two or more subsets of nanocrystals, the population characterized by a unique spectral code;
- wherein each said subset comprises a plurality of quantum dots of the same size and/or the same composition;
- wherein the unique spectral code of the population comprises at least one optical property defined by the interaction of the emission frequency of at least the first nanocrystal subset and the emission frequency of at least the second nanocrystal subset.
A composition for tagging and detecting objects, comprising:
- a population of nanocrystals comprising two or more subsets of nanocrystals that emit light when excited, each said subset comprising a plurality of quantum dots of the same size and/or the same composition, wherein the population has a unique spectral code, the spectral code comprising a first emission wavelength of a first nanocrystal subset and a second emission wavelength of a second nanocrystal subset, wherein the first and second emission wavelengths are the same.
Dependencies are inferred from the claim text.