Photoactive taggant materials comprising semiconductor nanoparticles and lanthanide ions

摘要

This invention provides, in one aspect, a procedure to use optically transparent nanocrystalline quantum dots to absorb UV light. This absorption process leads to an energy transfer to a chemically bound and chelated lanthanide ion that may emit light in either the visible spectrum (400-700 nm) or in the near infrared (700-1600 nm). This invention also provides methods for the use of these taggant materials in inks and aerosols used to disperse the taggant.